Research and analysis

Water situation: September 2025 summary

Updated 13 October 2025

Applies to England

It was the wettest month since September 2024 for England, as 149% of the long term average (LTA) rainfall for the month was received. Soil moisture deficits (SMD) remain high across parts of England, although recent wet conditions have reduced them in varying amounts, particularly in the north. Monthly mean river flows increased at almost all of our indicator sites, with just over half of sites classed as normal for the time of year. Groundwater levels continued their seasonal decline at all sites, and the majority of sites were classed as normal or lower at the end of September. Reservoir stocks were mixed at the end of September, as more than half saw a decrease in storage, while those that saw an increase generally rose by at least 10%. For England as a whole storage was 63%.

1. Rainfall

During September, England received 102mm of rainfall which represents 149% of the 1991 to 2020 LTA for the time of year, making it the wettest month for England since September 2024. More than three-quarters of hydrological areas received above average rainfall during September, and all the hydrological areas that received less than average rainfall were in east and south-east England. The wettest hydrological area as a percentage of LTA was the Eden in north-west England, which received 212% (218.3mm) of LTA rainfall in September. North West Grain in south-east England was the driest hydrological areas a percentage of LTA, having received 80% (38.4mm) of LTA rainfall.

Rainfall totals were classed as normal or higher for all hydrological areas in September. Just over a third were classed as normal, with the majority of these catchments found in east and south-east England. Another third received above normal for the time of year. Twenty-one hydrological areas (15% of the total) were classed as notably high for the time of year, and 14 (10%) were classed as exceptionally high, almost all of which were found in north-west and north-east England.

The 3-month cumulative rainfall totals were normal or below normal for most of England, with below normal catchments found in central, eastern and southern England. In Cumbria in the north-west, rainfall totals were above normal or notably high. Over the last 6-months, cumulative rainfall totals have been very mixed across England, although the majority were classed as normal or lower for the period. Across much of England, rainfall was classed as notably or exceptionally low for the period, however the far south-west and north-west both had above normal or higher rainfall. Twelve-month cumulative totals were normal or lower for almost all of England, with notably low totals in much of east and north-east England. In western areas, rainfall totals were mostly normal, with one above normal catchment in the north-west.

At a regional scale, rainfall totals were classed as normal in east and south-east England. South-west and central England both received above normal rainfall in September. North-east England received notably high rainfall, and the north-west was classed as exceptionally high having received almost twice the expected rainfall in the wettest September since 1968. For England as a whole, rainfall in September was classed as above normal for the time of year, and it was the first month of above average rainfall for the country since January.

2. Soil moisture deficit

A wetter than average month for much of England meant that SMD decreased across many parts of England at the end of the month. However, soils remain dry in east, south-east and central England, with east England seeing deficits close to the historic maximum. In south-west, north-west and north-east England, soils have become wetter.

Despite decreasing SMD in many areas, preceding dry conditions mean soils remain drier than average for the time of year in central, south-east and east England, with particularly dry soils in east England. Following a very wet month, soils in the north are now slightly wetter than would be expected for the time of year.

3. River flows

Monthly mean river flows increased at almost all of our indicator sites in September, with just 3 sites in east and south-east England seeing a decrease in flows. Just over half of sites were classed as normal for the time of year, most of which were found in south-west, south-east, central and east England. Six sites were classed as below normal for the time of year, and 3 were classed as notably low in the Rivers Yare, Lud and Ely Ouse across east England. Seventeen sites were classed as above normal or higher for the time of year, including all sites in north-west England. Eight sites were above normal and 7 were notably high. The Rivers Derwent and Lune in north-west England were both classed as exceptionally high for the time of year.

Our regional index sites reflected the overall picture, with all sites outside northern England being classed as normal for the time of year. In south-east England the Great Stour at Horton, and naturalised flows in the River Thames at Kingston were both classed as normal for the time of year. The Exe at Thorverton in south-west England was also classed as normal. The River Dove in central England and the Bedford Ouse in east England were both classed as normal for the time of year, with the Dove recovering from being classed as exceptionally low last month. In north-east England, Haydon Bridge on the South Tyne was classed as notably high for the time of year, having been notably low last month. In the north-west, the River Lune at Caton was classed as exceptionally high for the time of year after a quick increase in river flows in September.

4. Groundwater levels   

As all aquifers continue their typical early autumn recession, all of our indicator sites recorded a decrease in groundwater levels at the end of September. More than three-quarters of sites were classed as normal or lower for the time of year. Eleven sites were classed as normal, 4 were below normal, and 4 were notably low. Two sites were exceptionally low for the time of year, Chilgrove in the Chichester Chalk, and Tilshead in the Upper Hampshire Avon Chalk. In contrast, 3 sites were above normal including Crossley Hill and Coxmoor which are both in the Idle Torne Sandstone in central England. Weir Farm in the Bridgnorth Sandstone was notably high for the time of year, and Priors Heyes remains at exceptionally high levels as the West Cheshire Sandstone continues to recover from historic abstraction.

Our major aquifer index sites reflected this mixed picture. Skirwith in the Carlisle Basin Sandstone in north-west England was normal for the time of year, while Weir Farm in central England (Bridgnorth Sandstone) was notably high. Jackaments Bottom in the Burford Jurassic Limestone in south-east England was notably low for the time of year as the recession at the site began to ease. In north-east England, Dalton Estate Well in the Hull and East Riding Chalk was classed as notably low for the time of year. Redlands Hall in the Cam and Ely Ouse Chalk in east England was classed as normal at the end of September. In south-east England, the chalk aquifer sites were varied. Chilgrove in the South Downs was exceptionally low for the time of year. Meanwhile Little Bucket in the East Kent Stour Chalk was normal at the end of the month. At Stonor Park in the South West Chilterns Chalk in south-east England, groundwater levels continue a slow decline after very high levels over the past 2 winters and were classed as above normal for the third consecutive month.

5. Reservoir storage

At the end of September, reservoir storage had decreased at over half of the reservoirs and reservoir groups we report on, including the Dove group where storage decreased by 10%. Storage increases were focussed in north-east, north-west and central England where conditions had been wettest. Eleven reservoirs or groups recorded an increase, with the majority recording an increase over 10%, and the largest increase was the Pennines group which rose by 22%. Two reservoirs were classed as above normal for the time of year, Vyrnwy in Wales, and the Lower Lee group in south-east England. Seven reservoirs across England were classed as normal for the time of year.  Eleven reservoirs were classed as below normal, including the Yorkshire supply group where storage is now 46%. Three reservoirs were classed as notably low, including Ardingly in south-east England which is now just 30% full. The final 8 reservoirs were exceptionally low for the time of year, 6 of which are less than 50% full. In total 14 reservoirs are now less than half full. 

At a regional scale, reservoir storage was varied as very wet weather in parts of the country helped replenish storage. Three regions except the east, south-east and south-west saw an increase in storage during September, with the north-west increasing by 16%. Regional storage ranged from 45% in south-west England to 68% in north-east England. For England a whole, reservoir storage was 63%, after a 6% increase during September.

6. Forward look

October began with wet conditions across parts of England. By October 7, north-east and north-west England had already received a third of October’s LTA rainfall, with all other regions receiving more than 15% of LTA rainfall. For the rest of October, England will likely stay mostly settled and dry through mid-month, with sunny spells by day and chilly, occasionally foggy nights under high pressure. Temperatures should remain close to normal for the time of year. Later in the month, conditions are expected to turn more changeable, especially across western and northern areas, with an increasing chance of rain and stronger winds, while the south and east may remain drier for a little longer.

For the 3-month period from October to December, there is a lower than normal chance of a wet autumn for the UK, and a normal chance of a dry period. Regional variations in rainfall are to be expected, with south and east areas of the UK having a lower chance of being wet. Temperatures are more likely to be milder than average, while the chances of either a particularly windy or calm period are about equal.

6.1 Projections for river flows at key sites

By the end of March and September 2026, river flows across east and central England have a greater than normal chance of being below normal or lower. River flows in south-east England are most likely to be normal for the time of year. In other regions, there is no strong leaning, although below normal or lower river flows are slightly more likely.

6.2 Projections for groundwater levels in key aquifers

By the end of March 2026, groundwater levels have the greatest chance of being below normal or lower, and for south-west and south-west England groundwater levels have the greatest chance to be normal.

By the end of September 2026, groundwater levels have the greatest chance of being below normal or lower, and for south-west and north-west England groundwater levels have the greatest chance to be above normal or higher.

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.