Research and analysis

Water situation: April 2025 summary

Updated 13 May 2025

Applies to England

April was another dry month for much of England, with just 51% of long term average (LTA) rainfall being received for the country as a whole. Soil moisture deficits (SMD) continued to increase as would be expected at this time of year, but ongoing dry weather meant soils were drier than expected across most of England at the end of April. Monthly mean river flows decreased at the majority of sites we report on, and two-thirds of sites were classed as below normal or lower for the time of year. Groundwater levels declined at almost all of the sites we report on, although the majority were classed as normal or higher for the time of year. Reservoir stocks decreased at most sites in April, and England as a whole, ended the month with reservoir at storage 84% full.

1. Rainfall

During April, England received 28.3mm of rainfall which represents 51% of the 1961 to 1990 LTA for the time of year (50% of the 1961 to 1990 LTA). The majority of hydrological areas received below average rainfall for the time of year, including 14 which received less than 20% of the LTA in April. Just 10% (14) of hydrological areas received above LTA rainfall during April, all of which were in south-west England. The wettest hydrological area as a percentage of LTA was Fal and St Austell in south-west England, which received 211% of the LTA (137.4mm). Seaham Area, was the driest hydrological area as a percentage of LTA having received just 9% (4.4mm) of the LTA. Three hydrological areas had the driest February to April period since records began in 1871, including the Tyne and Ribble.

Rainfall totals in April were classed as below normal or lower in just over three-quarters of hydrological areas. This included all the hydrological areas in north-west and north-east England, where all 14 of the hydrological areas classed as exceptionally low were located. Twenty one (15%) hydrological areas were classed as normal for the time of year. In south-west England, rainfall during Easter week meant that all the hydrological areas classed as above normal or higher were in the region, including Fal and St Austell which was the only area to be classed as exceptionally high for the time of year.

The 3-month cumulative totals were classed as notably low or exceptionally low across most of England, with only the south-west seeing normal or higher totals due to recent rain. The 6-month cumulative rainfall totals were classed as normal across much of England, although the north-west and north-east were generally classed as below normal and lower, as were parts of east England. The 12-month cumulative totals were mixed, as most of England was classed as normal for the period, with patches of above normal and higher areas in south-east, south-west, central and southern parts of north-west England. In the north-east and parts of east and south-east England, 12-month cumulative rainfall totals were below normal or notably low, as were three hydrological areas on the Welsh border.

At a regional scale, rainfall was classed as normal in south-west England and below normal in east and south-east England. In central and north-west England, rainfall was classed as notably low and in north-east England exceptionally low rainfall was received. For both north-west and north-east England, it was the fourth consecutive month of below average rainfall, making it the driest start to a calendar year since 1929 for both regions. For England as a whole, it was the third consecutive month of below average rainfall, and the driest February to April period since 1956.

2. Soil moisture deficit

By the end of April, SMD had increased across most of England, except Devon, Cornwall and along the Welsh border where conditions were wettest. Soils were driest across southern England in parts of Wessex and the south-east.

Soils were drier than would be expected across almost all of England, except in Devon and Cornwall where above normal or higher rainfall during April left SMD around average for the time of year. In the central parts of south-east England, soils were much drier than would be expected at the end of April.

3. River flows

Monthly mean river flows decreased at almost all of our indicator sites in April, with just 4 sites seeing an increase in river flows, all of which were in south-west England. The majority of sites were classed as normal or lower for the time of year. Fifteen sites (28% of the total) were classed as exceptionally low for the time of year, and 8 sites (15%) were notably low, with all sites in north-west and north-east England in these classifications. Twelve sites (22%) were classed as below normal for the time of year, most of which were in the south and east of England, and 16 sites were classed as normal for April. The River Itchen and River Ver, both in south-east England, were classed as above normal and exceptionally high respectively as high groundwater levels continue to support river flows.

Six sites recorded their lowest April monthly mean flow on record (record start given in brackets), including 5 sites in north-east England:

• River Don at Doncaster (1959)
• River Swale at Crakehill Topcliffe (1980)
• South Tyne at Haydon Bridge (1974)
• River Wharfe at Tadcaster (1991)
• River Wear at Witton Park (1972)
• River Mersey at Ashton Weir (1976) in north-west England

During April, all regional index sites saw a decrease in monthly mean river flows compared to March. River flows at Offord (Bedford Ouse) in east England and Thorverton (River Exe) in south-west England were both classed as normal for the time of year. In south-east England, the Great Stour at Horton and River Thames at Kingston (naturalised flows) were both classed as below normal for the time of year. Three regional index sites were classed as exceptionally low for the time of year, the River Dove in central England, the South Tyne in north-east England, and the River Lune in north-west England.

4. Groundwater levels

At the end of April, all except one of our indicator sites saw a decrease in groundwater levels as aquifers began their usual seasonal decline. Just over half of all sites were classed as normal for the time of year. Wetwang (Hull and East Riding Chalk) in north-east England and Woodyates (Upper Dorset Stour Chalk) in south-west England were both classed as below normal for the time of year. Five sites (19% of the total) were classed as above normal for the time of year, and Coxmoor (Idle Torne Sandstone) in central England was classed as notably high. Three sites were classed as exceptionally high for the time of year, including Weir Farm (Bridgnorth Sandstone) in central England which recorded the highest end of April groundwater level since records began in 1983.

Groundwater levels at major aquifer index sites all decreased to the end of April. All index sites in chalk aquifers were classed as normal or higher for the time of year, including Redlands Hall (Cam and Ely Ouse Chalk) in east England which was above normal for the time of year, and Stonor Park (Chilterns Chalk) in south-east England which was exceptionally high for the time of year. Weir Farm (Bridgnorth Sandstone) in central England was exceptionally high for the time of year, while Skirwith (Carlisle Basin Sandstone) in north-west England was classed as normal for the time of year. Jackaments Bottom (Burford Jurassic Limestone) was classed as exceptionally low for the time of year.

5. Reservoir storage

At the end of April, reservoirs stocks decreased at two-thirds of the reservoirs and reservoir groups that we report on. The largest changes were seen in the Yorkshire supply group, the Pennines group, and at Haweswater and Thirlmere which all decreased by 12%. Almost half of reservoirs were classed as normal for the time of year, including the majority of reservoirs in south-east and east England. Six reservoirs (19%) were classed as below normal, including Blagdon, Clatworthy and Wimbleball in south-west England. Seven reservoirs were classed as notably low for the time of year, including all sites in north-east England, and 3 in central England. In the south-west, Roadford was above normal while Stithians was notably high for the time of year following a wet month in the area.

Haweswater and Thirlmere was classed as exceptionally low for the time of year as previously reported planned maintenance and low inflows have impacted the water resource zone. Similarly, the Dee system in Wales which supplies north-west England has been impacted by drawdown for safety works and low inflows, leaving it notably low for the time of year.

All regional stocks are at or below 95%, with the north-west having the lowest storage at 73%, and the south-east having the highest with 95%. Most regions are below average for the time of year except south-east and south-west England. By the end of April, total storage across England was 84% as overall stocks decreased by 5% since March. 

6. Forward look

May started with a week of very little rainfall across England and conditions are forecast to remain dry and sunny for most across the country throughout mid-May as high pressure continues to dominate. There is the potential of some heavy and thundery showers in places particularly in south-west England. Towards the end of May fairly typical weather for the time of year is most likely with fine and dry weather likely to dominate although this may be interspersed with occasional spells of rain and showers, with a risk of heavy rain and thunderstorms in places. Overall, temperatures in May will most likely be near or slightly above average.

For the 3-month period from May to July there is a higher than normal chance of conditions being warmer than average with an increased risk of heatwaves and heat related impacts. Rainfall is most likely to be similar to average, although heavy rain and thunderstorms at times remain a possibility, in places.

7. Projections for river flows at key sites

By the end of September 2025, river flows across most of England have the greatest chance of being normal or lower for the time of year.

By the end of March 2026, river flows across most of England have a greater chance of being normal or lower for the time of year, while in south-east England river flows have a greater chance of being normal or higher for the time of year.

8. Projections for groundwater levels in key aquifers

By September 2025, groundwater levels have the greater chance of being above normal or higher in north-west England. Groundwater levels across the rest of England have the greatest chance of being normal or lower for the time of year.

By March 2026, groundwater levels in central and north-east England have the greatest chance of being above normal or higher for the time of year. In all other regions, groundwater levels have the greatest chance of being normal or lower.

Author: National Water Resources Hydrology Team, nationalhydrology@environment-agency.gov.uk

All data are provisional and may be subject to revision. The views expressed in this document are not necessarily those of the Environment Agency. Its officers, servants or agents accept no liability for any loss or damage arising from the interpretation or use of the information, or reliance upon views contained in this report.