Research and analysis

Water situation: August 2026 summary

Updated 11 September 2026

Applies to England

August brought much needed rainfall to many parts of England, although all regions received rainfall below the August long term average (LTA). Rainfall in almost all hydrological areas was classed as normal or lower for the time of year. Soil moisture deficits (SMD) reduced modestly following the wet end to August, although all regions still have soils that are much drier than average for the time of year. Monthly mean river flows decreased at all sites, and all sites were classed as normal or lower for the time of year. Groundwater levels decreased as the expected seasonal decline continued, and most sites were classed as normal or lower at the end of August. Reservoir storage declined across all sites, and was 19.3% below average for the time of year for England as a whole at 58%.

1. Rainfall

During August, England received 58.5mm of rainfall, which represents 78% of the 1991 to 2020 LTA. Almost all hydrological areas received below average rainfall during August, with 23 in south-east and east England receiving less than 50% of the LTA. Above average totals were found in a band across the country between Liverpool and Hull. The wettest hydrological area by percentage of LTA was the Hull and Humber in north-east England, which received 143% of the LTA (96mm). The driest was in south-east England, where North London received just 26% of the LTA (14.9mm). Following an exceptionally dry July for many, 13 hydrological areas in east and south-east England recorded the driest July and August 2-month period since records began in 1871.

Rainfall was classed as normal or lower in all except 4 hydrological areas in August, with these 4 classed as above normal. Sixty-three (45% of the total) were classed as normal for the time of year. Fifty-eight (42%) in southern and north-east England, and along the Welsh border were classed as below normal, and 11 (8%) were classed as notably low, all of which were in south-east England. Near London, The Cut, Lower Wey, and North London were all classed as exceptionally low for the time of year.

The 3-month cumulative period was classed as below normal or lower for much of England, with just a handful of hydrological areas classed as normal for the period. Parts of east, central, south-west and north-east England had notably and exceptionally low totals in this period. Over the 6-month cumulative period, much of central, east and southern England was classed as exceptionally low. Elsewhere the period mainly saw below normal or notably low totals, although in north-west England rainfall was classed as normal or above normal. The 12-month cumulative period was mostly normal or higher in England, with just a handful of below normal or lower totals in east England. In the north-west and south-west, some hydrological areas had exceptionally high rainfall over the past 12 months.

At a regional scale, rainfall totals for August were classed as normal across most of England, with below normal rainfall in south-east and south-west England. South-east England received just 54% of LTA rainfall in August, meaning the July to August 2-month period was the driest on record since 1871 for the region. East England has now had below LTA rainfall every month since March, and within this it was the driest 5-month period for April to August since 1995. For England as a whole, rainfall was classed as normal for the time of year in August.

Standardised precipitation index (SPI) results for August were near normal for most of England, with moderately or severely dry conditions around London where rainfall totals were lowest. Over the last 3 and 6-month periods, moderately to extremely dry conditions are more widespread, reflecting the extended periods of low rainfall across much of England.

Standardised precipitation evapotranspiration index (SPEI) results for August were also near normal in much of northern and central England, and parts of east and south-west England. For much of southern England, SPEI results were moderately or severely dry, with some extremely dry conditions around London and the Home Counties. Following a summer of hot and extended periods of dry weather for many, the last 3 and 6-month periods were largely severely dry for England, with widespread extremely dry conditions across southern England over the 6-month period.

2. Soil moisture deficit

Rainfall in the last week of the month allowed SMD to decrease quickly across England at the end of August. SMD remains high across England, with the driest soils in south-east England.

At the end of August, soils were much drier than average across much of England, with particularly dry soils in south-west England and along the Welsh border. In east England, some areas have deficits close to average for the time of year. Around the Humber estuary soils are now slightly wetter than would be expected following above average rainfall in August. 

3. River flows

Monthly mean river flows decreased at three-quarters of indicator sites that we report on in August. All sites were classed as normal or lower for the time of year, with more than half classed as notably or exceptionally low. Seven sites were classed as normal for the time of year, many of which were in central England. Seventeen sites across England were classed as below normal and 12 were classed as notably low. Nineteen sites were classed as exceptionally low for the time of year, with all regions having sites in this class. The River Wye at Redbrook in south Wales recorded the lowest August monthly mean flow since records began in 1969. 

All regional sites had monthly mean river flows classed as below normal or lower for the time of year. The Bedford Ouse in east England and the River Dove in central England were both classed as below normal in August. The South Tyne in the north-east was the only regional site to see an increase in monthly mean river flows in August, however it was classed as notably low despite this increase. The River Exe in south-west England and the Great Stour in the south-east were also classed as notably low for the time of year.  The River Lune in north-west England was classed as exceptionally low for the time of year, as were the naturalised flows of the River Thames in south-east England.

4. Groundwater levels   

At the end of August, groundwater levels had decreased at almost all of the indicator sites we report on as the expected seasonal decline in groundwater resources continues. The majority of sites were classed as normal or lower for the time of year. Eleven sites (42% of the total) were classed as normal for the time of year and 7 (27%) were classed as below normal. One site (4%) was notably low, and two (8%) were classed as exceptionally low for the time of year, including Tilshead in the Upper Hampshire Avon Chalk in south-west England. In central and north-west England, a handful of sites were at the other end of the scale with 2 sites (8%) classed as above normal and 2 (8%) classed as notably high for the time of year. Coxmoor in central England recorded the highest end of August level since records began in 1990 and was classed as exceptionally high, as the impact of a wet winter continues to be felt in the slow responding Idle Torne Sandstone aquifer.

All major aquifer index sites recorded a decrease in groundwater levels at the end of August. Weir Farm in the Bridgnorth Sandstone in central England was classed as above normal for the time of year. In the Carlisle Basin and Eden Valley Sandstone in the north-west, Skirwith was classed as below normal for the time of year. Jackaments Bottom in the Burford Jurassic Limestone in south-east England was classed as exceptionally low for the time of year. Chalk aquifer sites were mixed at the end of August. In east and south-east England, Redlands Hall (Cam and Ely Ouse Chalk), Little Bucket (East Kent Stour Chalk) and Stonor Park (South West Chilterns Chalk) were all classed as normal. Dalton Estate in the Hull and East Riding Chalk in north-east England was below normal for the time of year. Chilgrove in the Chichester Chalk of south-east England was classed as notably low for August.

5. Reservoir storage

At the end of August, reservoir storage had decreased at all of the reservoirs or reservoir groups that we report on, with all except 4 recording a decrease of 10% or more. The largest decrease was recorded at Ardingly in south-east England where storage fell by 28%. Eleven reservoirs or reservoir groups have storage at or below 50%. Vyrnwy in Wales was the only reservoir to be classed as normal for the time of year, with all others classed as below normal or lower. Seven reservoirs were classed as below normal, and 14 were classed as notably low. Nine reservoirs were classed as exceptionally low, from Haweswater and Thirlmere in north-west England, to Wimbleball in the south-west.

Regional reservoir stocks decreased across England, with storage in central England falling by 15% to the end of August. Storage is below average for the time of year in all regions, and in east England it was near the historic minimum for the time of year. For England as a whole, storage was 58%, which is 19.3% below the LTA for the time of year, although it remains slightly higher than the same time in 2025.

6. Forward look

September has had a relatively wet start, with England receiving a third of the average rainfall for September in the first 8 days of the month. Conditions are expected to remain changeable through the middle of the month, with rain and showers moving in from the Atlantic. Rainfall will be most frequent in the north-west, with the south and east remaining drier. Later in September, high pressure is expected to dominate, bringing more settled conditions across England. High pressure and settled conditions are likely to remain to the end of the month.

For the 3-month period from September to November, conditions are more likely to be wet for the UK, with the latter part most likely to be wet. The chance of a warm autumn is higher than normal for the UK. Later in the period, the chance of rain and wind related impacts becomes slightly higher than normal.

6.1 Projections for river flows at key sites

By the end of September 2026, river flows have the highest chance of being below normal or lower across almost all of England, except in the south-east where river flows have a higher than average chance of being normal for the time of year.

By the end of March 2027, river flows in most regions of England have the highest chance of being below normal or lower, especially in east, central and north-west England. The exception is south-east England, where normal flows are more likely.

6.2 Projections for groundwater levels in key aquifers

By the end of September 2026, groundwater levels in central England have a higher than average chance of being above normal or higher. In south-east, north-east, and east England, groundwater levels are projected to have the highest chance of being normal for the time of year. In south-west and north-west England, groundwater levels have the highest chance of being below normal or lower.

By the end of March 2027, groundwater levels in central and south-west England have the highest chance of being normal but in the north-east, levels are projected to be above normal or higher. In the north-west groundwater levels have the highest chance of being below normal or lower and in south-east and east England this chance of low levels is higher than average.

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.