As of September 2024, the highest temperature ever recorded in the United Kingdom occurred on July 19th, 2022 at Coningsby, Lincolnshire. On this day, temperatures reached 40.3 degrees Celsius.

In 2022, several locations across the United Kingdom exceeded temperatures of more than 40 degrees Celsius for the time time on record. The village of Coningsby in eastern England reached 40.3 degrees Celsius on July 19, 2022. That same day, temperatures at Heathrow and St James's Park in London, as well as Pitsford, Northamptonshire, also recorded a maximum temperature of over 40 degrees Celsius. 2022 was the UK's hottest year on record.

This dataset is maintained by Max Eastwood (m.w.eastwood@lboro.ac.uk), Building Energy Research Group (BERG), School of Architecture, Building and Civil Engineering, Loughborough University.

This dataset provides the measured indoor dry bulb temperatures and surrounding weather conducted in the Loughborough Matched Pair test houses during summer 2022. The dataset is made publicly available here. This dataset includes: 1. README.txt: A Read Me file with more details of the study and the dataset. 2. Dataset_descriptor.pdf: a guidance document containing information on the measurment work carried out. 3. West_AT_10minute.csv: 10-minute dry bulb temperature measured in the West house (AT = Air Temperature) 4. East_AT_10minute.csv: 10-minute dry bulb temperature measured in the East house 5. Weather_20second.csv: 20-second weather data compiled from the test house weather station. Other information on the houses' geometry and construction can be found here: https://doi.org/10.17028/rd.lboro.8094575

England's highest monthly mean air temperatures are typically recorded in July and August of each year. Since 2015, the warmest mean temperature was measured in July 2018 at 18.8 degrees Celsius. On the other hand, February of that same year registered the coolest temperature, at 2.6 degrees Celsius. In April 2025, the mean air temperature was 10.3 degrees Celsius, slightly higher than the same month the previous year. The English weather England is the warmest region in the United Kingdom and the driest. In 2024, the average annual temperature in England amounted to 10.73 degrees Celsius – around 1.1 degrees above the national mean. That same year, precipitation in England stood at about 1,020 millimeters. By contrast, Scotland – the wettest region in the UK – recorded over 1,500 millimeters of rainfall in 2024. Temperatures on the rise Throughout the last decades, the average temperature in the United Kingdom has seen an upward trend, reaching a record high in 2022. Global temperatures have experienced a similar pattern over the same period. This gradual increase in the Earth's average temperature is primarily due to various human activities, such as burning fossil fuels and deforestation, which lead to the emission of greenhouse gases. This phenomenon has severe consequences, including more frequent and intense weather events, rising sea levels, and adverse effects on human health and the environment.

The UK daily temperature data contain maximum and minimum temperatures (air, grass and concrete slab) measured over a period of up to 24 hours. The measurements were recorded by observation stations operated by the Met Office across the UK and transmitted within NCM, DLY3208 or AWSDLY messages. The data span from 1853 to 2023. For details on measurement techniques, including calibration information and changes in measurements, see section 5.2 of the MIDAS User Guide linked to from this record. Soil temperature data may be found in the UK soil temperature datasets linked from this record.

This version supersedes the previous version of this dataset and a change log is available in the archive, and in the linked documentation for this record, detailing the differences between this version and the previous version. The change logs detail new, replaced and removed data. These include the addition of data for calendar year 2023.

This dataset is part of the Midas-open dataset collection made available by the Met Office under the UK Open Government Licence, containing only UK mainland land surface observations owned or operated by the Met Office. It is a subset of the fuller, restricted Met Office Integrated Data Archive System (MIDAS) Land and Marine Surface Stations dataset, also available through the Centre for Environmental Data Analysis - see the related dataset section on this record. Currently this represents approximately 95% of available daily temperature observations within the full MIDAS collection.

The United Kingdom recorded its hottest-ever year in 2022, with an average temperature of 10.03 degrees Celsius. Since the start of temperature recording in 1884, the 10 warmest years recorded in the UK have been from 2003 onwards. Weather conditions are predicted to become more extreme due to climate change.

Temperature in the United Kingdom increased to 10.14 celsius in 2023 from 10.13 celsius in 2022. This dataset includes a chart with historical data for the United Kingdom Average Temperature.

The Coastal Temperature Network consists of Cefas (and predecessor) originated data and data from external suppliers, who have agreed their data can be published as part of the network (Jones, 1981). The earliest data are from 1875 (Owers Light vessel) and have been supplied by the Met Office. The longest continuous record provided here is from Eastbourne (1892–2014). Sampling is from piers and breakwaters 50-200m from the shore where possible (Jones, 1981). The present network covers the temperature condition of coastal waters around the coast of England and Wales and was operationally combined with the salinity and temperature conditions across the Southern Bight of the North Sea. Individuals on behalf of Cefas, councils, companies and other organisations have obtained records of coastal sea surface temperature, for some stations, of more than 100-year duration. Approximately half of the stations started recording coastal temperatures in the mid–1960s. There are 41 stations in England and Wales where 20 out of 41 are still in operation. Cefas observers record coastal sea surface temperature using calibrated thermometers approximately 6 – 14 times per month, usually close to the time of high water. Other organisations record sea surface temperature ranging from daily values to monthly means. Since 2012, the data from Dover Council is recorded every minute. Data are published as monthly means (Joyce, 2006); the extracted data are the measurements used to calculate the means. The Cefas instruments are calibrated at Lowestoft to an accuracy of ±0.1°C. The accuracy of other instruments is not known, but is thought to be at least to an accuracy of ±0.2°C. The ferry route observers record offshore sea surface temperature from the ships main seawater pipe using a calibrated thermometer 4 times a month. The temperatures are recorded to at least an accuracy of ±0.2°C. The seawater samples are taken from the sea water main pipe to the harbour pump about 1.5 metres inboard. Quality assurance checks are applied to the data for each station by comparing the current dataset with either a 5 or 10 year running mean for each month. The data is first tested to see whether it is normally distributed i.e. whether all the data are close to average. The standard deviation is calculated to see how tightly the data are clustered around the mean; three standard deviations are then calculated to account for 99% of the data. If the data are outside this range (3 std dev) then the value is flagged and removed from subsequent analysis. See Joyce (2006) for details of the duration and history of individual datasets. Inevitably, there are changes in the number and location of monitoring stations over such a long period. At its peak the network reported on about 100 locations. This has reduced to around 30 in the late 20th century. Jones & Jeffs (1991) show the locations of early coastal stations. In addition, operating sites are moved and data recording upgraded, e.g. Eastbourne from a manual coastal site (see Joyce, 2006) to, in 2013, an electronic logging system mounted on an offshore buoy. These changes are reflected in the positions associated with the extracted data. See https://www.cefas.co.uk/cefas-data-hub/sea-temperature-and-salinity-trends/_ for a full description of the originating system which has sea-surface temperature (and sometimes salinity) data collected at a number of coastal sites around England and Wales, some operated by volunteers, some operated by local councils and some associated with power stations. The longest time-series include those from Eastbourne (1892 - present), Dover (1926 - present) and Port Erin, Isle of Man (1903 - present) although most time series began in the 1960s or 1970s.

.. _https://www.cefas.co.uk/cefas-data-hub/sea-temperature-and-salinity-trends/: https://www.cefas.co.uk/cefas-data-hub/sea-temperature-and-salinity-trends/

During the heat wave in 2022, the highest temperature recorded in the United Kingdom was 40.3 degrees Celsius on July 19 at Coningsby, Lincolnshire. An unprecedented extreme heatwave was experienced in the United Kingdom from 16 to 19 July 2022, and extreme temperatures at over 40°C were recorded for the first time since recording of temperatures began.

This dataset contains meteorological observations taken from 72 locations around Great Britain, Ireland and Europe published in the 1900-1910 Met Office Daily Weather Reports (DWRs). These records were produced as part of the Operation Weather Rescue project.

Twice daily observations of mean sea level pressure and dry bulb temperature, along with daily wet bulb, maximum and minimum temperatures and total rainfall, were sent to the Met Office via telegraph for publication the DWRs. Some of the locations cover the entire 11 year period whereas others stopped reporting and may have been replaced by another location, and some locations were included in the DWRs from a later date. Additional observations of mean sea level pressure, dry bulb temperature and wet bulb temperature at 2pm are included for 1900 but these observations were no longer included in the DWRs after 1900. From November 1908 the German stations replaced wet bulb temperature with relative humidity.

The data is stored in two formats: in daily csv files with observations for each station and in Station Exchange Format (SEF) files for each station in separate variables. SEF is a human-readable text format saved as .tsv (tab separated values). In the csv files units are inches of mercury (inHg) for mean sea level pressure, degrees Fahrenheit (F) for all temperature variables, inches for rainfall and percent (%) for relative humidity. In the SEF files the units are hectopascals (hPa) for mean sea level pressure, degrees Celsius (C) for all temperature variables, millimetres (mm) for rainfall and percent for relative humidity.

The tables provided show the national weather records. To ensure consistency, these weather records are only given for stations with standard instruments and exposure. Although some records have been broken by non-standard stations, these are not accepted as official records for this reason.

        Records are provided as follows:

        For temperature by country, by month and by district for the following:
        Highest daily maximum temperature
        Highest daily minimum temperature
        Lowest daily maximum temperature
        Lowest daily minimum temperature

        For rainfall 
        by country, for highest 24-hour rainfall totals for a rainfall day (0900 - 0900 GMT) 
        by period, in days for UK rainfall records for consecutive rainfall days (0900 - 0900 GMT) 
        by period, in minutes for UK rainfall records for short durations (from 5 to 180 minutes)

        For sunshine hours by country, for highest monthly sunshine records 

        For gust speed by country and district (for sites below 250m), for highest gust speed

This dataset has been extracted as part of an exercise to assemble "all" Cefas Temperature Data and publish it in a Data paper. It is one of 17 Cefas data sources assembled.

This data source differs from the others in this collection because it arises from an investigation into the potential for Citizen Science to contribute to assessments of the marine environment. The dataset is derived from a database containing over 7,000 records of temperature data collected from temperature compensated dive computers. The lowest temperature is recorded from the thermal sensor. The unprocessed data were then subjected to a quality control process that compared the temperature with the relevant sea surface temperature (obtained from OSTIA – Operational Sea Surface Temperature and Sea Ice Analysis – http://ghrsst–pp.metoffice.com/pages/latest_analysis/ostia.html_).

There was a linear correlation between the sea surface temperature and the recorded temperature at depth. Values exceeding a specified difference from the surface temperature (5°C) were excluded. This resulted in a quality assured dataset of just over 5,000 records (including freshwater and lake data). The subset of global dataset provided covers the UK shelf.

The 5°C threshold is derived from previous analyses of the performance of dive computers.

.. _http://ghrsst–pp.metoffice.com/pages/latest_analysis/ostia.html: http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html

The UK hourly weather observation data contain meteorological values measured on an hourly time scale. The measurements of the concrete state, wind speed and direction, cloud type and amount, visibility, and temperature were recorded by observation stations operated by the Met Office across the UK and transmitted within SYNOP, DLY3208, AWSHRLY and NCM messages. The sunshine duration measurements were transmitted in the HSUN3445 message. The data spans from 1875 to 2022.

This version supersedes the previous version of this dataset and a change log is available in the archive, and in the linked documentation for this record, detailing the differences between this version and the previous version. The change logs detail new, replaced and removed data. These include the addition of data for calendar year 2022.

For details on observing practice see the message type information in the MIDAS User Guide linked from this record and relevant sections for parameter types.

This dataset is part of the Midas-open dataset collection made available by the Met Office under the UK Open Government Licence, containing only UK mainland land surface observations owned or operated by Met Office. It is a subset of the fuller, restricted Met Office Integrated Data Archive System (MIDAS) Land and Marine Surface Stations dataset, also available through the Centre for Environmental Data Analysis - see the related dataset section on this record. Note, METAR message types are not included in the Open version of this dataset. Those data may be accessed via the full MIDAS hourly weather data.

The United Kingdom's hottest summer ever recorded was in 2018, with an average temperature of 15.76 degrees Celsius. Meanwhile, 2023 saw the eighth hottest summer in the UK, with an average temperature of 15.35 degrees. In the last couple of decades, five of the top 10 warmest summers in the UK were recorded. New temperature records in 2022 In summer 2022, record-breaking temperatures of more than 40 degrees Celsius were recorded at several locations across the UK. Accordingly, 2022 was also the UK's warmest year on record, with the average annual temperature rising above 10 degrees Celsius for the first time. Since temperature recording began in 1884, the hottest years documented in the country have all occurred after 2003. England: the warmest country in the UK Amongst the countries that comprise the United Kingdom, England has generally seen the highest annual mean temperatures. In 2022, England’s average temperature also reached a new record high, at nearly 11 degrees Celsius. And while it’s not a typical sight in the United Kingdom, England also registered the most hours of sunshine on average, with Scotland being the gloomiest country out of the four.

TEMPEST (Tracking Extremes of Meteorological Phenomena Experienced in Space and Time) is the major output of the Arts and Humanities Research Council (AHRC) funded project “Spaces of Experience and Horizons of Expectation: Extreme Weather in the UK, Past, Present and Future (which ran from 2013-2017)".

TEMPEST was designed as a freely accessible and user-friendly database resource on the UK’s weather and climate history. TEMPEST is comprised of narrative accounts of extreme weather events of all types, extracted from documentary materials located in a range of archival repositories in the UK (consequentially, please see the quality statement note below concerning data issues). The information has been extracted from a wide range of documents, including letters, diaries, church records, school log-books and many others. The entries span more than 400 years - some as early as 1346 - of weather history and relate to places across the UK, though the data search was focused in five case-study regions: Central England, Southwest England, East Anglia, Wales, and Northwest Scotland.

Each event entry or narrative has been assigned to at least one weather type, is dated (at least to a year), and is geographically referenced (using digital coordinates). Many also contain material relating to the impacts of the weather event and responses to it. In addition to information on extreme weather events, TEMPEST contains details of the original documents, their authors, and the collections and repositories in which they are held. TEMPEST is searchable by all of these fields.

Users are advised to read the quality statement carefully with regards to possible issues in date and location accuracy and the way "extreme" events were documented. Additionally, users should be aware that the period covered by the dataset includes the change from the Julian to Gregorian calendar. In order to manage that change 11 days were omitted from the year 1752, i.e. the day after the 2 September 1752 was 14 September, in accordance with the Calendar Act of 1751. Until September 1752 the New Year began on 25 March (Lady Day) but dual dating was commonplace for many years before, adding a further layer of complication to events that took place from 1 January to 24 March, and making 1751 a short year running from 25 March to 31 December! Scotland had changed the start of the year to 1 January in 1600. Where clear, the Gregorian calendar date has been used, providing further details in the notes section.

This dataset has been extracted as part of an exercise to assemble "all" Cefas Temperature Data and publish it in a Data paper. It is one of 17 Cefas data sources assembled.

SmartBuoys are autonomous marine monitoring systems making high frequency measurements of physical, chemical and biological parameters (Greenwood et al., 2010). They have been deployed as part of the UK marine eutrophication monitoring programme.

[Updated 28/01/25 to fix an issue in the ‘Lower’ values, which were not fully representing the range of uncertainty. ‘Median’ and ‘Higher’ values remain unchanged. The size of the change varies by grid cell and fixed period/global warming levels but the average difference between the 'lower' values before and after this update is 0.0.]What does the data show? The Annual Count of Extreme Summer Days is the number of days per year where the maximum daily temperature is above 35°C. It measures how many times the threshold is exceeded (not by how much) in a year. Note, the term ‘extreme summer days’ is used to refer to the threshold and temperatures above 35°C outside the summer months also contribute to the annual count. The results should be interpreted as an approximation of the projected number of days when the threshold is exceeded as there will be many factors such as natural variability and local scale processes that the climate model is unable to represent.The Annual Count of Extreme Summer Days is calculated for two baseline (historical) periods 1981-2000 (corresponding to 0.51°C warming) and 2001-2020 (corresponding to 0.87°C warming) and for global warming levels of 1.5°C, 2.0°C, 2.5°C, 3.0°C, 4.0°C above the pre-industrial (1850-1900) period. This enables users to compare the future number of extreme summer days to previous values.What are the possible societal impacts?The Annual Count of Extreme Summer Days indicates increased health risks, transport disruption and damage to infrastructure from high temperatures. It is based on exceeding a maximum daily temperature of 35°C. Impacts include:Increased heat related illnesses, hospital admissions or death affecting not just the vulnerable. Transport disruption due to overheating of road and railway infrastructure.Other metrics such as the Annual Count of Summer Days (days above 25°C), Annual Count of Hot Summer Days (days above 30°C) and the Annual Count of Tropical Nights (where the minimum temperature does not fall below 20°C) also indicate impacts from high temperatures, however they use different temperature thresholds.What is a global warming level?The Annual Count of Extreme Summer Days is calculated from the UKCP18 regional climate projections using the high emissions scenario (RCP 8.5) where greenhouse gas emissions continue to grow. Instead of considering future climate change during specific time periods (e.g. decades) for this scenario, the dataset is calculated at various levels of global warming relative to the pre-industrial (1850-1900) period. The world has already warmed by around 1.1°C (between 1850–1900 and 2011–2020), whilst this dataset allows for the exploration of greater levels of warming. The global warming levels available in this dataset are 1.5°C, 2°C, 2.5°C, 3°C and 4°C. The data at each warming level was calculated using a 21 year period. These 21 year periods are calculated by taking 10 years either side of the first year at which the global warming level is reached. This time will be different for different model ensemble members. To calculate the value for the Annual Count of Extreme Summer Days, an average is taken across the 21 year period. Therefore, the Annual Count of Extreme Summer Days show the number of extreme summer days that could occur each year, for each given level of warming. We cannot provide a precise likelihood for particular emission scenarios being followed in the real world future. However, we do note that RCP8.5 corresponds to emissions considerably above those expected with current international policy agreements. The results are also expressed for several global warming levels because we do not yet know which level will be reached in the real climate as it will depend on future greenhouse emission choices and the sensitivity of the climate system, which is uncertain. Estimates based on the assumption of current international agreements on greenhouse gas emissions suggest a median warming level in the region of 2.4-2.8°C, but it could either be higher or lower than this level.What are the naming conventions and how do I explore the data?This data contains a field for each global warming level and two baselines. They are named ‘ESD’ (where ESD means Extreme Summer Days, the warming level or baseline, and ‘upper’ ‘median’ or ‘lower’ as per the description below. E.g. ‘Extreme Summer Days 2.5 median’ is the median value for the 2.5°C warming level. Decimal points are included in field aliases but not field names e.g. ‘Extreme Summer Days 2.5 median’ is ‘ExtremeSummerDays_25_median’. To understand how to explore the data, see this page: https://storymaps.arcgis.com/stories/457e7a2bc73e40b089fac0e47c63a578Please note, if viewing in ArcGIS Map Viewer, the map will default to ‘ESD 2.0°C median’ values.What do the ‘median’, ‘upper’, and ‘lower’ values mean?Climate models are numerical representations of the climate system. To capture uncertainty in projections for the future, an ensemble, or group, of climate models are run. Each ensemble member has slightly different starting conditions or model set-ups. Considering all of the model outcomes gives users a range of plausible conditions which could occur in the future. For this dataset, the model projections consist of 12 separate ensemble members. To select which ensemble members to use, the Annual Count of Extreme Summer Days was calculated for each ensemble member and they were then ranked in order from lowest to highest for each location. The ‘lower’ fields are the second lowest ranked ensemble member. The ‘upper’ fields are the second highest ranked ensemble member. The ‘median’ field is the central value of the ensemble.This gives a median value, and a spread of the ensemble members indicating the range of possible outcomes in the projections. This spread of outputs can be used to infer the uncertainty in the projections. The larger the difference between the lower and upper fields, the greater the uncertainty.‘Lower’, ‘median’ and ‘upper’ are also given for the baseline periods as these values also come from the model that was used to produce the projections. This allows a fair comparison between the model projections and recent past. Useful linksThis dataset was calculated following the methodology in the ‘Future Changes to high impact weather in the UK’ report and uses the same temperature thresholds as the 'State of the UK Climate' report.Further information on the UK Climate Projections (UKCP).Further information on understanding climate data within the Met Office Climate Data Portal.

This dataset has been extracted as part of an exercise to assemble "all" Cefas Temperature Data and publish it in a Data paper. It is one of 17 Cefas data sources assembled. Sampling of plankton has been carried out by Cefas since the 1940’s. In recent decades sampling has mainly been concentrated on fish eggs and larvae, and other zooplankton. Samples were collected using ‘high–speed towed nets’ that capture plankton from the surface to near–seabed. At each sampling position the sampler was deployed in an oblique tow from the surface to within approximately 2 m of the seabed. Veering and hauling speeds were manually adjusted with the aim of sampling each depth band equally. Since the early 1980’s CTD sensor packages were fitted to the plankton samplers to continuously monitor temperature and salinity throughout each deployment. From 1982 until 2003 the Guildline CTD system was used. Subsequently the ESM2 Profiler/mini CTD Logger (see 3.17) has been used.

For each sampler deployment a raw data file was created from the logged values. Data were logged at intervals varying from 2 to 5 seconds. Raw files were subsequently post–processed using custom–written software (two different packages over the time period covered here) to produce calibrated profiles of the environmental values measured. Depending on the software used and level of post–processing undertaken by the operator either the whole profile (i.e. both dive and haul portions of the deployment) or just the dive part of the profile, were derived. Pressure averaged profiles may also have been created where mean values were ‘binned’ into depth bands of 1 m width.

Pressure (Depth), Temperature and Conductivity (CTD) profiles collected on Cefas (or DFR) plankton research cruises. The data in this archive broadly cover the European Shelf. Original output files are varied in data format according to the collection system used and the level of post-processing carried out.

[Updated 28/01/25 to fix an issue in the ‘Lower’ values, which were not fully representing the range of uncertainty. ‘Median’ and ‘Higher’ values remain unchanged. The size of the change varies by grid cell and fixed period/global warming levels but the average percentage change between the 'lower' values before and after this update is -1%.]What does the data show? A Heating Degree Day (HDD) is a day in which the average temperature is below 15.5°C. It is the number of degrees above this threshold that counts as a Heating Degree Day. For example if the average temperature for a specific day is 15°C, this would contribute 0.5 Heating Degree Days to the annual sum, alternatively an average temperature of 10.5°C would contribute 5 Heating Degree Days. Given the data shows the annual sum of Heating Degree Days, this value can be above 365 in some parts of the UK.Annual Heating Degree Days is calculated for two baseline (historical) periods 1981-2000 (corresponding to 0.51°C warming) and 2001-2020 (corresponding to 0.87°C warming) and for global warming levels of 1.5°C, 2.0°C, 2.5°C, 3.0°C, 4.0°C above the pre-industrial (1850-1900) period. This enables users to compare the future number of HDD to previous values.What are the possible societal impacts?Heating Degree Days indicate the energy demand for heating due to cold days. A higher number of HDD means an increase in power consumption for heating, therefore this index is useful for predicting future changes in energy demand for heating.What is a global warming level?Annual Heating Degree Days are calculated from the UKCP18 regional climate projections using the high emissions scenario (RCP 8.5) where greenhouse gas emissions continue to grow. Instead of considering future climate change during specific time periods (e.g. decades) for this scenario, the dataset is calculated at various levels of global warming relative to the pre-industrial (1850-1900) period. The world has already warmed by around 1.1°C (between 1850–1900 and 2011–2020), whilst this dataset allows for the exploration of greater levels of warming. The global warming levels available in this dataset are 1.5°C, 2°C, 2.5°C, 3°C and 4°C. The data at each warming level was calculated using a 21 year period. These 21 year periods are calculated by taking 10 years either side of the first year at which the global warming level is reached. This time will be different for different model ensemble members. To calculate the value for the Annual Heating Degree Days, an average is taken across the 21 year period. Therefore, the Annual Heating Degree Days show the number of heating degree days that could occur each year, for each given level of warming. We cannot provide a precise likelihood for particular emission scenarios being followed in the real world future. However, we do note that RCP8.5 corresponds to emissions considerably above those expected with current international policy agreements. The results are also expressed for several global warming levels because we do not yet know which level will be reached in the real climate as it will depend on future greenhouse emission choices and the sensitivity of the climate system, which is uncertain. Estimates based on the assumption of current international agreements on greenhouse gas emissions suggest a median warming level in the region of 2.4-2.8°C, but it could either be higher or lower than this level.What are the naming conventions and how do I explore the data?This data contains a field for each warming level and two baselines. They are named ‘HDD’ (Heating Degree Days), the warming level or baseline, and 'upper' 'median' or 'lower' as per the description below. E.g. 'HDD 2.5 median' is the median value for the 2.5°C projection. Decimal points are included in field aliases but not field names e.g. 'HDD 2.5 median' is 'HDD_25_median'. To understand how to explore the data, see this page: https://storymaps.arcgis.com/stories/457e7a2bc73e40b089fac0e47c63a578Please note, if viewing in ArcGIS Map Viewer, the map will default to ‘HDD 2.0°C median’ values.What do the ‘median’, ‘upper’, and ‘lower’ values mean?Climate models are numerical representations of the climate system. To capture uncertainty in projections for the future, an ensemble, or group, of climate models are run. Each ensemble member has slightly different starting conditions or model set-ups. Considering all of the model outcomes gives users a range of plausible conditions which could occur in the future. For this dataset, the model projections consist of 12 separate ensemble members. To select which ensemble members to use, Annual Heating Degree Days were calculated for each ensemble member and they were then ranked in order from lowest to highest for each location. The ‘lower’ fields are the second lowest ranked ensemble member. The ‘upper’ fields are the second highest ranked ensemble member. The ‘median’ field is the central value of the ensemble.This gives a median value, and a spread of the ensemble members indicating the range of possible outcomes in the projections. This spread of outputs can be used to infer the uncertainty in the projections. The larger the difference between the lower and upper fields, the greater the uncertainty.‘Lower’, ‘median’ and ‘upper’ are also given for the baseline periods as these values also come from the model that was used to produce the projections. This allows a fair comparison between the model projections and recent past. Useful linksThis dataset was calculated following the methodology in the ‘Future Changes to high impact weather in the UK’ report and uses the same temperature thresholds as the 'State of the UK Climate' report.Further information on the UK Climate Projections (UKCP).Further information on understanding climate data within the Met Office Climate Data Portal.

The highest average temperature recorded in 2024 until November was in August, at 16.8 degrees Celsius. Since 2015, the highest average daily temperature in the UK was registered in July 2018, at 18.7 degrees Celsius. The summer of 2018 was the joint hottest since institutions began recording temperatures in 1910. One noticeable anomaly during this period was in December 2015, when the average daily temperature reached 9.5 degrees Celsius. This month also experienced the highest monthly rainfall in the UK since before 2014, with England, Wales, and Scotland suffering widespread flooding. Daily hours of sunshine Unsurprisingly, the heat wave that spread across the British Isles in 2018 was the result of particularly sunny weather. July 2018 saw an average of 8.7 daily sun hours in the United Kingdom. This was more hours of sun than was recorded in July 2024, which only saw 5.8 hours of sun. Temperatures are on the rise Since the 1960s, there has been an increase in regional temperatures across the UK. Between 1961 and 1990, temperatures in England averaged nine degrees Celsius, and from 2013 to 2022, average temperatures in the country had increased to 10.3 degrees Celsius. Due to its relatively southern location, England continues to rank as the warmest country in the UK.