Research and analysis

Water situation: August 2025 summary

Updated 11 September 2025

Applies to England

It was the driest August since 2003, and England received 42% of the long term average (LTA) rainfall for the month. Most of the month’s rain fell during the last few days of the month, which led to some decreases in soil moisture deficits (SMD) in many regions, although preceding dry conditions mean soils remain much drier than would be expected for the time of year across most of England. Monthly mean river flows decreased at almost all sites we report on, with just over half of sites classed as notably low or exceptionally low for the time of year. Groundwater levels continued their seasonal decline and just under half of sites were classed as normal for the time of year at the end of August. Reservoir stocks decreased at all of the reservoirs we report on, with England as a whole ending August with 57% storage.

1. Rainfall

During August, England received 31.3mm of rainfall which represents 42% of the 1991 to 2020 LTA for the time of year. It was the driest August since 2003. The majority of August’s rain fell in the final 5 days of the month, with most of the month being dry across much of England. All hydrological areas received below average rainfall during August. The wettest hydrological area as a percentage of LTA was Kent in north-west England, which received 92% (135mm) of LTA rainfall. The driest hydrological area was the Soar in central England, where just 13mm of rainfall was received, which is 20% of the LTA.

Rainfall totals were classed as normal or lower for all hydrological areas in August, with 60% classed as notably or exceptionally low. Of the 26 hydrological areas classed as normal for the time of year, the majority were in south-west England and along the south coast, with a handful in the far north-west. Below normal rainfall was received in 30 hydrological areas, the majority of which were in south-east and south-west England. Fifty-seven hydrological areas were classed as notably low for the time of year, and 26 were classed as exceptionally low, most of which were in central, north-west and north-east England.

The 3-month cumulative totals were classed as below normal or lower across most of England. Normal rainfall was received in south-east and south-west England, with totals in the north-west normal or higher for the time of year. It was the warmest summer period (June, July and August) for England since records began in 1884. The 6-month cumulative totals were classed as exceptionally low across most of England, with the south-west and north-west being the only areas to see normal rainfall in the period. Fifteen hydrological areas have had the driest 6 months (March to August) since records began in 1871. Over the 12-month period, rainfall has been normal across much of England. In east and north-east England, conditions have been drier with totals classed as below normal or lower, with exceptionally low totals in the far north-east.

At a regional scale, August rainfall was classed as below normal for south-west England and notably low for south-east and north-west England. East, central and north-east England were classed as exceptionally low for the time of year. For England as a whole, rainfall was classed as notably low. This was the seventh consecutive month of below average rainfall in east and central England, with both experiencing the driest February to August period since records began in 1871. England has also had seven consecutive months of below average rainfall, and it was the driest February to August period since 1976.

2. Soil moisture deficit

Rainfall in the final days of August saw soil moisture deficits decrease in many parts of England, most notably in south-west England. However, despite this wet end to the month, soils remain very dry across most of England due to preceding, ongoing dry conditions. The exceptions are in Cumbria and parts of Devon, where soils were almost fully wet at the end of August.

Soils were drier than would be expected across most of England at the end of August, particularly in central and north-east areas. In the far north-west a handful of hydrological areas have soils slightly wetter than would be expected for the time of year. 

3. River flows

Monthly mean river flows decreased at almost all of our indicator sites in August, with just over half of sites being classed as notably or exceptionally low for the time of year. Ten sites (19% of the total) were classed as normal for the time of year, most of which were in east and south-east England. Fifteen sites (28%) were classed as below normal for the time of year. A third of sites were classed as notably low, and 10 sites (19%) were classed as exceptionally low, most of which were in north-east and central England. Just one site was classed as above normal, the River Ver in south-east England, where healthy groundwater resources continue to support river flows.

Four sites, three in north-east England and one in Wales, recorded their lowest August monthly mean river flow on record (record start given in brackets):

• River Derwent at Buttercrambe (1973)
• River Swale at Crakehill Topcliffe (1980)
• River Till at Heaton Mill (2001)
• River Wye at Redbrook in Wales (1969)

Offord on the Bedford Ouse in east England was the only regional index site to be classed as normal for the time of year. Horton on the Great Stour in south-east England was classed as below normal. Thorverton on the River Exe in south-west England, Haydon Bridge on the South Tyne in north-east England and naturalised flows at Kingston on the River Thames in the south-east were all classed as notably low for the time of year. The River Dove, as measured at Marston-on-Dove in central England, was classed as exceptionally low for the time of year.

4. Groundwater levels   

At the end of August, almost all of our indicator sites recorded a decrease in groundwater levels as aquifers continued their seasonal recessions. Almost half of sites were classed as normal for the time of year. Four sites were classed as above normal for the time of year. Priors Hayes in the West Cheshire Sandstone in north-west England, was classed as exceptionally high, and recorded its highest end of August value since records began in 1972. Three sites in chalk aquifers in the south-east, east and north-east of England were classed as below normal for the time of year. Three more chalk sites, in north-east and south-west England were classed as below normal at the end of August. Three sites were classed as exceptionally low for the time of year, including two index sites below and Tilshead in the Upper Hampshire Avon Chalk aquifer.

This mixed picture was reflected by our major aquifer index sites. In east and south-east England, chalk index sites ranged from above normal to exceptionally low levels. With Redlands Hall (Cam and Ely Ouse Chalk) and Little Bucket (East Kent Stour Chalk) both normal for the time of year, while Stonor Park (South West Chilterns Chalk) was above normal, and Chilgrove (Chichester Chalk) was exceptionally low. Meanwhile Dalton Estate Well in north-east England (Hull and East Riding Chalk) was classed as notably low for the time of year. In the north-west, Skirwith (Carlisle Basin Sandstone) was classed as normal for the time of year, while Weir Farm (Bridgnorth Sandstone) in central England was above normal. Finally, Jackaments Bottom in the Burford Jurassic Limestone in south-east England was classed as exceptionally low for the time of year for the fifth consecutive month.

5. Reservoir storage

At the end of August, reservoir stocks had decreased at all of the reservoirs and reservoir groups that we report on, with three-quarters seeing a decrease of more than 10% during the month. Clywedog reservoir, which supplies central England from Wales, and the Dove group in central England saw the largest decreases of 24% and 22% respectively. The Lower Lee group in south-east England saw the smallest change of just 3%, and was the only reservoir to be classed as above normal for the time of year. Almost two-thirds of reservoirs and reservoir groups that we report on were classed as notably or exceptionally low for the time of year. Six reservoirs were classed as below normal and 4 were classed as normal. Twelve reservoirs and reservoir groups are now less than half full.

All regional reservoir stocks decreased during August, with south-west England seeing the biggest decrease of 16%. All other regions decreased by at least 10%, and central, north-west and south-west England are all below 50% full. All regions remain below average for the time of year. For England as a whole, storage at the end of August was 57%, after a 12% decrease since the end of July. As a comparison, storage for England at the end of August 2022 was 55%.

6. Forward look

September began with wetter, more unsettled conditions across southern England with the other areas of England also experiencing heavy rainfall at times. The unsettled conditions are expected to continue through mid-September with the possibility of heavy rain and strong winds for many areas of England though parts of the east may see lower totals. There may be some drier spells later in the month, particularly in southern England. The changeable conditions will persist throughout England towards the end of the month with spells of rain and showers, heavy at times, possibly thundery. Towards the end of the month some fog patches are possible where skies are clear and the nights become colder.

For the 3-month period from September to November for the UK, there is a higher than normal chance of a warmer, wetter and windier autumn period with an increased likelihood of stormier spells. Later on in the period, the chance of rain and wind related impacts are slightly higher than normal.

6.1 Projections for river flows at key sites

By the end of September 2025, river flows across most of England have the highest likelihood of being normal or below normal, with river flows in south east England having the greatest probability of being normal. By the end of March 2026, river flows across most of England have the greatest chance of being below normal or lower, with river flows in south east England having the greatest chance of being normal or higher.

6.2 Projections for groundwater levels in key aquifers

By the end of September 2025, groundwater levels have the highest probability of being below normal for north east and south west England. Across the rest of England groundwater levels have the greatest chance to be normal. By the end of March 2026, groundwater levels across most of England have an increased likelihood of being below normal or lower with only groundwater levels in the south-west likely to be normal.

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.