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.

The United Kingdom experienced an average of 1,242.1 millimeters of rainfall in 2024, a decrease of 5.8 percent in comparison to the previous year. While 2024 saw substantial rainfall, it did not surpass the thus-far peak of the century, with 1,373 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 1,571.7 millimeters and 1,600.8 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.

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

What does the data show?

This data shows the monthly averages of rainfall amount (mm) for 1981-2010 from CRU TS (v. 4.06) dataset. It is provided on the WGS84 grid which measures approximately 60km x 60km (latitude x longitude) at the equator. This is the same as the 60km grid used by UKCP18 global datasets.

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 average of the monthly total rainfall in March throughout 1981-2010.

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

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

Useful links

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

A set of single tile images in the form of map overlays to show recent rain rates in mm/hour over the UK.

        Single tile map layer images are updated every 15 minutes with a 15 minute delay due to processing times.

Between 2001 and 2023, 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 2023, the annual average rainfall in the UK surpassed 1,381 millimeters.

Monthly rainfall

On average, rainfall is most common at the start and end of the year. Between 2014 and 2023, 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. In 2023, the average rainfall in Scotland amounted to approximately 1,574 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.

5 km resolution composite data and plots from the Met Office's UK rainfall radars via the Met Office NIMROD system. The NIMROD system is a very short range forecasting system used by the Met Office. Data are available from 2004 until present at UK stations and detail rain-rate observations taken every 5 minutes. Each file has been compressed and then stored within daily tar archive files.

The Quantifying Flood Risk of Extreme Events using Density Forecasts Based on a New Digital Archive and Weather Ensemble Predictions Project is a Natural Environment Research Council (NERC) Flood Risk for Extreme Events (FREE) Research Programme project (Round 1 - NE/E002013/1 - Duration January 2007 - December 2008) led by Dr Patrick McSharry, University of Oxford. The dataset contains a collection of rainfall depth maxima data, dating back to 1860, plus associated description documents and rainfall maps of extreme events across the UK, have been used. All of these products have been digitised from the paper version of the British Rainfall publication, and are now archived at the BADC to enable easy access for future use and the wider community.

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.

Rainfall in England amounted to 161 millimeters in February 2020. This was the most rainfall recorded in a single month during the period of consideration. Meanwhile, the driest month during this period was in May 2020, in which less than 10 millimeters of rain fell. In September 2024, England's precipitation amounted to 133.5 millimeters.

Dual-polar products from the Met Office's Deanhill C-band rain radar, Whiteparish, Wiltshire, England. Data include augmented ldr (linear depolarization ratio) and zdr (differential reflectivity) scan data (both long and short pulse). The radar is a C-band (5.3 cm wavelength) radar and data are received by the Nimrod system at 5 minute intervals.

What does the data show?

The data shows monthly averages of rainfall amount (mm) for 1991-2020 from HadUK gridded data. It is provided on a 2km British National Grid (BNG).

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 average 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:

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

A forecast map layer covering the UK showing precipitation. Precipitation is any product of the condensation of atmospheric water vapour that falls under gravity. The main forms of precipitation include drizzle, rain, sleet, snow and hail. Single tile map layer images are provided three hourly from T+0 to T+36. The map layer is provided without a map, the boundary box for this image is 48 to 61 degrees north and 12 degrees west to 5 degrees east. The image layers are currently made available in a Mercator projection, it is the same projection used by Bing maps, OpenStreetMap, Google maps, MapQuest, Yahoo maps, and others.

Since 2015, the greatest monthly rainfall deviation in the United Kingdom occurred in February 2020. This month saw a considerable increase of 139 millimeters from the long-term mean. In comparison, the same month in 2023 saw a decrease of almost 40 millimeters compared to the mean from 2002 to 2021.

5 km resolution rain rate data from Met Office's Cobbacombe Cross C-band rain radar, Devon, England as part of the NIMROD, very short range forecasting system used by the Met Office. 5 km rain rate data are available from April 2004 until present. Radar images from the C-band (5.3 cm wavelength) radar are received by the Nimrod system 5 minute intervals respectively.

This dataset contains UK Nimrod rainfall radar data for 2016-2019 as used in the Skillful Precipitation Nowcasting Using Deep Generative Model of Radar paper by DeepMind.

This dataset contains scan data from the National Centre for Atmospheric Science Atmospheric Measurement and Observation Facility's mobile X-band radar during the Radar Applications in Northern England (RAIN-E) project. The radar collected data at Sandwith, near Whitehaven in Cumbria from October 2018 to December 2020.

2 km resolution rain rate data from Met Office's Wardon Hill C-band rain radar, Dorset, England as part of the NIMROD, very short range forecasting system used by the Met Office. 1 km rain rate data are available from 2006 until present. Radar images from the C-band (5.3 cm wavelength) radar are received by the Nimrod system 5 minute intervals respectively.

Please note that this radar is operated for research purposes only and thus subject to changes in operation and data are subject to interruptions.

Data from the Cobbacombe Cross, Dean Hill or Jersey radars provide coverage for the same area covered by the Wardon Hill radar.

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.

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