Average rainfall in the United Kingdom has generally been higher during the fourth quarter of every year. In the period of consideration, the highest rainfall average was recorded in the fourth quarter of 2011, at 738.6 millimeters.

The United Kingdom experienced an average of ******* millimeters of rainfall in 2024, a decrease of *** percent in comparison to the previous year. While 2024 saw substantial rainfall, it did not surpass the thus-far peak of the century, with ***** millimeters of rain recorded in 2000. Regional variations and seasonal patterns Rainfall distribution across the UK is far from uniform, with Scotland and Wales consistently receiving the highest annual precipitation. In 2024, they recorded an average of ******* millimeters and ******* millimeters, respectively, significantly above the UK’s average. This disparity is largely due to both countries’ mountainous terrain, which is more susceptible to Atlantic weather systems. Seasonally, the wettest months in the UK typically occur in the winter, with the highest precipitation levels seen between November and February. Climate change impact on UK weather Climate change is influencing UK weather patterns, leading to warmer and wetter conditions overall. While annual rainfall fluctuates, there is a trend towards more extreme weather events. For example, 2020 and 2022 saw rain deviations from the long-term mean in the UK of more than 100 millimeters in February. As weather patterns continue to evolve, monitoring rainfall trends remains crucial for understanding and adapting to a changing climate.

Between 2001 and 2024, the average rainfall in the United Kingdom varied greatly. In 2010, rainfall dropped to a low of 1,020 millimeters, which was a noticeable decrease when compared to the previous year. However, the following year, rainfall increased significantly to a peak of 1,889 millimeters. During the period in consideration, rainfall rarely rose above 1,500 millimeters. In 2024, the annual average rainfall in the UK surpassed 1,386 millimeters. Monthly rainfall On average, rainfall is most common at the start and end of the year. Between 2014 and 2024, monthly rainfall peaked in December 2015 at approximately 217 millimeters. This was the first of only two times during this period that the average monthly rainfall rose above 200 millimeters. This was a deviation from December’s long-term mean of some 134 millimeters. Rainfall highest in Scotland In the United Kingdom, rain is often concentrated around mountainous regions such as the Scottish Highlands, so it is no surprise to see that – on average – it is Scotland that receives the most rainfall annually. However, in 2024, Wales received the highest rainfall amounting to approximately 1,600 millimeters. Geographically, it is the north and west of the United Kingdom that receives the lion's share of rain, as it is more susceptible to rainfall coming in from the Atlantic.

What does the data show?

This data shows annual averages of precipitation (mm/day) for 2050-2079 from the UKCP18 regional climate projections. The data is for the high emissions scenario (RCP8.5).

Limitations of the data

We recommend the use of multiple grid cells or an average of grid cells around a point of interest to help users get a sense of the variability in the area. This will provide a more robust set of values for informing decisions based on the data.

What are the naming conventions and how do I explore the data?

This data contains a field for the average over the period. They are named 'pr' (precipitation), the month, and 'upper' 'median' or 'lower'. E.g. 'pr Median' is the median value.

To understand how to explore the data, see this page: https://storymaps.arcgis.com/stories/457e7a2bc73e40b089fac0e47c63a578

Please note, if viewing in ArcGIS Map Viewer, the map will default to ‘pr January 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 averages of precipitation for 2050-2079 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.

Data source

pr_rcp85_land-rcm_uk_12km_12_ann-30y_200912-207911.nc (median)

pr_rcp85_land-rcm_uk_12km_05_ann-30y_200912-207911.nc (lower)

pr_rcp85_land-rcm_uk_12km_04_ann-30y_200912-207911.nc (upper)

UKCP18 v20190731 (downloaded 04/11/2021)

Useful links

Further information on the UK Climate Projections (UKCP). Further information on understanding climate data within the Met Office Climate Data Portal

The wettest months in the United Kingdom tend to be at the start and end of the year. In the period of consideration, the greatest measurement of rainfall was nearly 217 millimeters, recorded in December 2015. The lowest level of rainfall was recorded in April 2021, at 20.6 millimeters. Rainy days The British Isles are known for their wet weather, and in 2024 there were approximately 164 rain days in the United Kingdom. A rainday is when more than one millimeter of rain falls within a day. Over the past 30 years, the greatest number of rain days was recorded in the year 2000. In that year, the average annual rainfall in the UK amounted to 1,242.1 millimeters. Climate change According to the Met Office, climate change in the United Kingdom has resulted in the weather getting warmer and wetter. In 2022, the annual average temperature in the country reached a new record high, surpassing 10 degrees Celsius for the first time. This represented an increase of nearly two degrees Celsius when compared to the annual average temperature recorded in 1910. In a recent survey conducted amongst UK residents, almost 80 percent of respondents had concerns about climate change.

Precipitation in the United Kingdom decreased to 1275.23 mm in 2024 from 1405.56 mm in 2023. This dataset includes a chart with historical data for the United Kingdom Average Precipitation.

1 km gridded estimates of daily and monthly rainfall for Great-Britain and Northern Ireland (together with approximately 3000 km2 of catchment in the Republic of Ireland) from 1890 to 2019. The rainfall estimates are derived from the Met Office national database of observed precipitation. To derive the estimates, monthly and daily (when complete month available) precipitation totals from the UK rain gauge network are used. The natural neighbour interpolation methodology, including a normalisation step based on average annual rainfall, was used to generate the daily and monthly estimates. The estimated rainfall on a given day refers to the rainfall amount precipitated in 24 hours between 9am on that day until 9am on the following day. The CEH-GEAR dataset has been developed according to the guidance provided in BS 7843-4:2012.

What does the data show?

The data shows monthly averages of precipitation amount (mm) for 1991-2020 from HadUK gridded data. It is provided on a 12km British National Grid (BNG).

Limitations of the dataWe recommend the use of multiple grid cells or an average of grid cells around a point of interest to help users get a sense of the variability in the area. This will provide a more robust set of values for informing decisions based on the data.What are the naming conventions and how do I explore the data?

This data contains a field for each month’s average over the period. They are named 'pr' (precipitation) and the month. E.g. 'pr March' is the rainfall amount for March in the period 1991-2020.

To understand how to explore the data, see this page: https://storymaps.arcgis.com/stories/457e7a2bc73e40b089fac0e47c63a578

Please note, if viewing in ArcGIS Map Viewer, the map will default to ‘pr January’ values.

Data source: 

·
Version: HadUK-Grid v1.1.0.0 (downloaded 26/08/2022)

·
Source: https://catalogue.ceda.ac.uk/uuid/652cea3b8b4446f7bff73be0ce99ba0f

·
Filename: rainfall_hadukgrid_uk_12km_mon-30y_199101-202012.nc

Useful links

·
Further information on HadUK-Grid

·
Further information on understanding climate data within the Met Office Climate Data Portal

For the purposes of this lesson and those that follow, a specimen data (Monthly Maximum Air Temperatures for 2019 at the 25km resolution) taken from from the HadUK-Grid archive and published as a Feature Layer in ArcGIS OnlineIn this activity we will see how to search ArcGIS Online for data and add it to the Map Viewer.

Copyright Notice & Acknowledgements

All information regarding MET Office copyright policy can be found at: https://www.metoffice.gov.uk/about-us/legal#licences All data was sourced from: https://www.metoffice.gov.uk/research/climate/maps-and-data/historic-station-data

Context

The MET Office has been responsible for monitoring UK Weather since it's inception in 1854. 36 stations in the UK (often located in RAF bases) gather information that is used to predict future weather patterns and issue public advice. More recently, these large datasets have become useful to investigate how the UK climate has changed over the past 150+ years.

Content

Columns: - year: Year in which the measurements were taken - month: Month in which the measurements were taken - tmax: Mean daily maximum temperature (°C) - tmin: Mean daily minimum temperature (°C) - af: Days of air frost recorded that month (days) - rain: Total rainfall (mm) - sun: Total sunshine duration (hours) - station: Station location where measurement was recorded

Data was collected from the MET Office website as separate station csv files and combined to one data frame with a station label assigned. All characters (*,#,---) that denoted things such as the equipment used were removed from the set. Some sections include significant amounts of NA values. Note that a 0 entry does not denote an NA value but a score of 0 in that measured field.

Inspiration

Has the UK climate changed since the Victorian era? How does any climate change impact the UK in terms of weather risks? Are some regions more affected than others?

A good starting point: The monthly mean temperature is calculated from the average of the mean daily maximum and mean daily minimum temperature i.e. (tmax+tmin)/2.

What does the data show?

This data shows the annual number of 10mm rainfall days (days where rainfall is equal to or greater than 10mm) averaged over the 1991-2020 period. The data is from the HadUK-Grid v.1.1.0.0 dataset and is provided on the 2km British National Grid (BNG).

What are the naming conventions and how do I explore the data?

This data contains a field for the average over the period, named ‘Rainfall 10mm Days’.

To understand how to explore the data, see this page: https://storymaps.arcgis.com/stories/457e7a2bc73e40b089fac0e47c63a578

Data source

HadUK-Grid v1.1.0.0 (downloaded 11/03/2022)

Useful links

Further information on HadUK-Grid Further information on understanding climate data within the Met Office Climate Data Portal

What does the data show?

This data shows the monthly averages of rainfall amount (mm) for 2040-2069 using a combination of the CRU TS (v. 4.06) and UKCP18 global RCP2.6 datasets. The RCP2.6 scenario is an aggressive mitigation scenario where greenhouse gas emissions are strongly reduced.

The data combines a baseline (1981-2010) value from CRU TS (v. 4.06) with a percentage change relative to 1981-2010 from UKCP18 global. Where the baseline value was <1mm/month, the projection value has been replaced with 'Null' because the percentage change may be unreliable with a very small baseline.

The data is provided on the WGS84 grid which measures approximately 60km x 60km (latitude x longitude) at the equator.

Limitations of the data

We recommend the use of multiple grid cells or an average of grid cells around a point of interest to help users get a sense of the variability in the area. This will provide a more robust set of values for informing decisions based on the data.

What are the naming conventions and how do I explore the data?

This data contains a field for each month’s average over the period. They are named 'pr' (precipitation), the month and ‘upper’ ‘median’ or ‘lower’. E.g. ‘pr Mar Lower’ is the average of monthly-total rainfall in March throughout 2040-2069, in the second lowest ensemble member.

To understand how to explore the data, see this page: https://storymaps.arcgis.com/stories/457e7a2bc73e40b089fac0e47c63a578

Please note, if viewing in ArcGIS Map Viewer, the map will default to ‘pr Jan 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.

To select which ensemble members to use, the monthly averages of precipitation for the period 2040-2069 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.

Data source

CRU TS v. 4.06 - (downloaded 12/07/22)

UKCP18 v.20200110 (downloaded 17/08/22)

Useful links

Further information on CRU TS Further information on the UK Climate Projections (UKCP) Further information on understanding climate data within the Met Office Climate Data Portal

This Normal Year Precipitation Patterns dataset complements 13 other datasets as part of a study that compared ancient settlement patterns with modern environmental conditions in the Jazira region of Syria. This study examined settlement distribution and density patterns over the past five millennia using archaeological survey reports and French 1930s 1:200,000 scale maps to locate and map archaeological sites. An archaeological site dataset was created and compared to and modelled with soil, geology, terrain (contour), surface and subsurface hydrology and normal and dry year precipitation pattern datasets; there are also three spreadsheet datasets providing 1963 precipitation and temperature readings collected at three locations in the region. The environmental datasets were created to account for ancient and modern population subsistence activities, which comprise barley and wheat farming and livestock grazing. These environmental datasets were subsequently modelled with the archaeological site dataset, as well as, land use and population density datasets for the Jazira region. Ancient trade routes were also mapped and factored into the model, and a comparison was made to ascertain if there was a correlation between ancient and modern settlement patterns and environmental conditions; the latter influencing subsistence activities. This dataset was created to show precipitation patterns for normal years in the Jazira region; annual precipitation is measured in millimetres. The purpose of mapping was to compare precipitation and settlement patterns in the region. The northern half of the Jazira region receives adequate annual rainfall to sustain dry farming activities; during dry seasons, suitable rainfall is restricted to the northern edges of the region and in higher elevations.

What does the data show?

This data shows the monthly averages of rainfall amount (mm) for 2070-2099 using a combination of the CRU TS (v. 4.06) and UKCP18 global RCP2.6 datasets. The RCP2.6 scenario is an aggressive mitigation scenario where greenhouse gas emissions are strongly reduced.

The data combines a baseline (1981-2010) value from CRU TS (v. 4.06) with a percentage change relative to 1981-2010 from UKCP18 global. Where the baseline value was <1mm/month, the projection value has been replaced with 'Null' because the percentage change may be unreliable with a very small baseline.

The data is provided on the WGS84 grid which measures approximately 60km x 60km (latitude x longitude) at the equator.

Limitations of the data

We recommend the use of multiple grid cells or an average of grid cells around a point of interest to help users get a sense of the variability in the area. This will provide a more robust set of values for informing decisions based on the data.

What are the naming conventions and how do I explore the data?

This data contains a field for each month’s average over the period. They are named 'pr' (precipitation), the month and ‘upper’ ‘median’ or ‘lower’. E.g. ‘pr Mar Lower’ is the average of monthly-total rainfall in March throughout 2070-2099, in the second lowest ensemble member.

To understand how to explore the data, see this page: https://storymaps.arcgis.com/stories/457e7a2bc73e40b089fac0e47c63a578

Please note, if viewing in ArcGIS Map Viewer, the map will default to ‘pr Jan 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.

To select which ensemble members to use, the monthly averages of precipitation for the period 2070-2099 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.

Data source

CRU TS v. 4.06 - (downloaded 12/07/22)

UKCP18 v.20200110 (downloaded 17/08/22)

Useful links

Further information on CRU TS Further information on the UK Climate Projections (UKCP) Further information on understanding climate data within the Met Office Climate Data Portal

Data, maps and figures for climate suitability of UK species in current and future climate scenarios (2 and 4 degree) at a 10km resolution. Species covered: Araneae; Birds; Bryophytes; Centipedes; Coleoptera; Dermaptera; Dictyoptera; Diptera; Hymenoptera; Lepidoptera; Millipedes; Odonata; Orthoptera; Plants. These data used the latest modelling techniques and analytical frameworks to explore how changes in climate suitability, as a result of projected climate change, might affect the distributions of species in Great Britain. The analysis was undertaken for 3000+ species of a wide range of terrestrial taxa (from vascular plants and bryophytes to spiders and beetles and birds). The spatial outputs from this project are maps and data showing the current and projected changes in the climate suitability for species in both their historical ranges and outside their historical ranges for both "current" (1961-90 - representing a baseline covering the period when the species data were collected, and before the more recent rapid rises in global temperatures) and future climate scenarios (2 and 4 degree Celsius global temperature increases). The data are presented at a 10km resolution. These data used the latest modelling techniques and analytical frameworks to explore how changes in climate suitability, as a result of projected climate change, might affect the distributions of species in Great Britain. The analysis was undertaken for 3000+ species of a wide range of terrestrial taxa (from vascular plants and bryophytes to spiders and beetles and birds). The spatial outputs from this project are maps and data showing the current and projected changes in the climate suitability for species in both their historical ranges and outside their historical ranges for both "current" (1961-90 - representing a baseline covering the period when the species data were collected, and before the more recent rapid rises in global temperatures) and future climate scenarios (2 and 4 degree Celsius global temperature increases). The data are presented at a 10km resolution.

These data and maps represents the best information on the potential impacts of climate change on the distribution of thousands of species to help guide conservation managers in how to prepare for some of the impacts of climate change in England. The dataset will be of value to resverve managers, conservation planners, and those implenting Government polcies such as Local Nature Recovery Strategies, the national Nature Recovery Network, the designation of SSSIs and NNRs, Biodiversity Net Gain, Protected Sites and Species Conservation Strategies.

The users just need to be aware that, like most such information, they need to be used carefully and in conjunction with other sources of information, place-based knowledge and knowledge of the ecological requirements of particular species.

Met Office Historical Station Data

A dataset wrangled from the UK Met Office and available at https://www.metoffice.gov.uk/research/climate/maps-and-data/historic-station-data. This dataset is updated on a monthly basis (usually the first or second working day of the calendar month).

The wrangling consists of: - Cleaning some data errors. - Adding data about relative sunshine duration based upon the location of the station. - Combining the separate text files for each station into a single CSV file.

A series of London-wide climate risk maps has been produced to analyse climate exposure and vulnerability across Greater London. These maps were produced by Bloomberg Associates in collaboration with the Greater London Authority to help the GLA and other London-based organisations deliver equitable responses to the impacts of climate change and target resources to support communities at highest risk. Climate vulnerability relates to people’s exposure to climate impacts like flooding or heatwaves, but also to personal and social factors that affect their ability to cope with and respond to extreme events. High climate risk coincides with areas of income and health inequalities. A series of citywide maps overlays key metrics to identify areas within London that are most exposed to climate impacts with high concentrations of vulnerable populations. In 2022, Bloomberg Associates updated London’s climate risk maps to include additional data layers at a finer geographic scale (LSOA boundaries). These maps were built upon earlier maps using the Transport for London (Tfl) hexagonal grid (often referred to in this report as the “Hex Grid”). In addition, the map interface was updated to allow users to compare individual data layers to the Overall, Heat and Flooding Climate Risk maps. Users can now also see the specific metrics for each individual LSOA to understand which factors are driving risk throughout the city. In 2024, Bloomberg Associates further modernized the climate risk maps by updating the social factor layers to employ more recent (2021) census data. In addition, air temperature at the surface was used in place of just surface temperature, as a more accurate assessment of felt heat. The Mayor is addressing these climate risks and inequalities through the work of the London Recovery Board, which includes projects and programmes to address climate risks and ensure a green recovery from the pandemic. Ambitious policies in the London Environment Strategy and recently published new London Plan are also addressing London’s climate risks. The data layers at the LSOA level are available here to use in GIS software: Climate risk scores (overall, heat, and flood): https://cityhall.maps.arcgis.com/home/item.html?id=22484ef240624e149735ca1aaa4c9ade# Social and physical risk variables: https://cityhall.maps.arcgis.com/home/item.html?id=bc06d80731f146b393f8631a0f98c213#

UNEP/GRID Documentation Summary for Data Set: Mean Annual Precipitation from GRID and UEA/CRU Background The World Atlas of Desertification was published by UNEP in 1992 as the result of a cooperative effort between UNEP's Desertification Control Programme Activity Centre (DC/PAC), the Global Environment Monitoring System (GEMS) and the Global Resource Information Database (GRID).GRID compiled and/or derived most of the global and regional databases, produced the maps and carried out the data analyses and tabulations for the Atlas, assisted by a Technical Advisory Group on Desertification Assessment and Mapping composed of various international experts. The Atlas includes information and many maps derived from the Global Assessment of Human-Induced Soil Degradation (GLASOD), as conducted in 1990 by the International Soil Reference and Information Centre (ISRIC) at Wageningen, The Netherlands, on behalf of UNEP. Aside from GLASOD's data on soil degradation, and in order to capture the multi-dimensional nature of global desertification processes, other data layers relating to global climate and vegetation were compiled by GRID for inclusion in the 1992 World Atlas of Desertification. Both the source climate data and advice on the production of all climate surfaces were obtained from the Climate Research Unit of the University of East Anglia (UEA/CRU), U.K. GRID Production of the Mean Annual Precipitation Surface For the purpose of Desertification Atlas map production, the GRID-Nairobi data analysts required data from a fairly dense network of global climate stations.

Scotland has seen its annual rainfall vary since 1994, though it usually received more than 1,500 millimeters of rain per year. However, in 2003 the recorded rainfall amounted to 1,209 millimeters, which was the lowest during this period. Rainfall peaked in 2011 at 1,862 millimeters. In 2024, annual rainfall totals reached 1,609 millimeters. Wet end to the year The wettest months in Scotland tend to be those at the end of each year, with December of 2015 recording higher than normal levels of rain at 322 millimeters. That same month there was an average of 25.4 raindays. Raindays are defined as those where more than 1mm of rain falls. Why is it so wet in Scotland? With its mountainous landscape, it is no coincidence that on average it is Scotland that receives the most annual rain in the UK. The wettest parts of the UK are generally in mountainous regions, with the Western Highlands prone to high levels of rain. Here, rainfall can be 3,000 millimeters per year. However, the East of Scotland can see levels as low as 800 millimeters. This is often due to rainfall from the Atlantic weather systems coming in from the West and as these systems move east, rain deposits reduce.

Monthly reports. Contains maps and data for England, Wale, Scotland and Northern Ireland