Research and analysis

Water situation: September 2026 summary

Updated 13 October 2026

Applies to England

September was the third consecutive month of below long term average (LTA) rainfall for England, with all regions except the north-west classed as below normal for the time of year. Soil moisture deficits (SMDs) increased across most of England, with soils much drier than average in much of south and east England. Monthly mean river flows increased following recent rainfall, and all sites were classed as normal or lower for the time of year. Groundwater levels continued to decline at many sites as is expected at this time of year, and the majority were classed as normal or lower. Reservoir storage declined across much of England, and three-quarters of reservoirs or reservoir groups were classed as notably or exceptionally low for the time of year. 

1. Rainfall

England received 44.8mm of rainfall during September, which represents 65% of the 1991 to 2020 LTA. The majority of hydrological areas received below average rainfall, with above average totals mainly found in north-west England. The wettest hydrological area by percentage of LTA was the Esk in Cumbria, which received 129% of the LTA (197.4mm). In stark contrast to August when it was the wettest hydrological area, in September the Hull and Humber received just 29% of LTA rainfall (14.9mm) making it the driest.

Rainfall was classed as normal or lower in all except one hydrological area in September, with the Esk (Cumbria) being the only hydrological area classed as above normal for the time of year. Sixty-one (44% of the total), were classed as normal for the time of year, mainly found in north-west, west and parts of south-east England. Sixty-eight (49%) were classed as below normal for the time of year. Eight (6%) were classed as notably low, and one (1%) was classed as exceptionally low, with all of these hydrological areas found in north-east and east England.

The 3-month cumulative period was classed as notably or exceptionally low for most of England. In the north-west and parts of central and south-west England, rainfall totals for the period were classed as normal or below normal. Over the 6-month period, rainfall totals were classed as exceptionally low for most of England, with normal, below normal or notably low totals in the north-west and south-west. Seventeen hydrological areas have recorded their driest April to September 6-month period since records began in 1871, and for a further 69 it is in the top 5. The 12-month cumulative period was normal or higher for much of England, although parts of south-east and east England were classed as below normal or notably low for this period.

At a regional scale, rainfall was classed as below normal across most of England, with the north-west the only region to be classed as normal for the time of year. East England received 52% of LTA rainfall in September, while the north-west received 99%. It was the seventh consecutive month of below average rainfall in central and east England, with east England recording the driest March to September period since records began in 1871. All other regions recorded their third consecutive month of below average rainfall and for the south-east it was the driest 3-month July to September period since records began in 1871. For England as a whole rainfall was classed as below normal for the time of year in September.

Standardised precipitation index (SPI) results for September were near normal for much of England, with moderately dry conditions in north-east England, and severely dry conditions in the Hull and Humber. Over the last 3 and 6-month periods, severely dry and extremely dry conditions have been widespread across much of England, with only the north-west being near normal. The 12-month period has been near normal, with moderately to extremely wet conditions in parts of south-west, central and north-west England. In the east of England some areas were moderately dry over the 12-month period.

Standardised precipitation evapotranspiration index (SPEI) results for September were near normal for much of England. In east and north-east England and in a band through the south-east into Devon, conditions were moderately to extremely dry in September. For the 3-month period, severely and extremely dry conditions were widespread across England, with moderately dry and near normal conditions confined to the north-west. Over the last 6-month period, conditions were extremely dry across almost all of England, while the north-west was moderately dry or near normal. The 12-month period was near normal for much of England, although moderately and severely dry conditions occurred across east, south-east and parts of north-east England.

2. Soil moisture deficit

Despite rainfall early in the month helping to diminish SMD, dry weather for the rest of the month saw larger SMDs at the end of September than at the end of the month before. SMDs remain large across much of England, although in the north-west and south-west SMDs have reduced following recent rainfall. The driest soils are in east, south-east and south-west England.

At the end of September, soils were much drier than would be expected across most of England, with particularly dry soils along the south coast, in south Wales and in the far north-east of England. In north-west England, SMDs are closer to average, with some near the Scottish border now wetter than would be expected for the time of year.

3. River flows

Monthly mean river flows increased at most of the indicator sites we report on in September and all sites were classed as normal or lower for the time of year. Seventeen sites were classed as normal for the time of year, including all sites in north-west England. Nineteen were classed as below normal, with many found in central, east and south-east England. Sixteen sites in north-east, south-east and south-west England were classed as notably low for the time of year. Three sites were classed exceptionally low for the time of year. This included the River Yare in east England and the River Tone in the south-west which recorded their lowest September monthly mean river flow since records began in 1970 and 1961 respectively.

All regional sites had monthly mean river flows classed as normal or lower for the time of year. The Bedford Ouse in east England and the River Lune in the north-west were both classed as normal. The River Dove in central England, south Tyne in the north-east and the Great Stour in east England were all classed as below normal for the time of year. The River Exe in the south-west and the naturalised river flows on the River Thames in south-east England were both classed as notably low for the time of year.

4. Groundwater levels   

At the end of September, groundwater levels had decreased at most of the indicator sites we report on, as the seasonal decline of groundwater resources continues. Almost all 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 5 (19%) were classed as below normal. Four sites (15%) were classed as notably low, including Wetwang in the Hull and East Riding Chalk in the north-east and Woodyates in the Upper Dorset Stour chalk aquifer in south-west England. Tilshead in the Upper Hampshire Avon chalk aquifer in the south-west and Chipstead in the Epsom North Downs Chalk in south-east England were classed as exceptionally low for the time of year. At the other end of the scale, in the sandstone aquifers of central and north-west England, one site was classed as above normal, 2 were notably high and one was exceptionally high.

Groundwater levels had decreased at all major aquifer index sites at the end of September. Chalk aquifer sites were mixed at the end of September. In east and south-east England, Redlands Hall in the Cam and Ely Ouse Chalk, Little Bucket in the East Kent Stour Chalk and Stonor Park in the 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 September. 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 notably low for the time of year.

5. Reservoir storage

At the end of September, reservoir storage had decreased at the majority of the reservoirs and reservoir groups that we report on. Six remained stable or increased, with the largest increase of 8% recorded at Clywedog in Wales. Eight reservoirs or reservoir groups recorded a decrease of 10% or more, with Ardingly in south-east England recording the largest decrease of 16%. Seventeen reservoirs or reservoir groups had storage at or below 50% at the end of September. Three-quarters of reservoirs or groups were classed as notably or exceptionally low for the time of year. Vyrnwy in Wales and Blagdon in the south-west were the only reservoirs to be classed as normal for the time of year. Six reservoirs or groups were classed as below normal. Six reservoirs or groups in central, east, south-east and south-west England were classed as exceptionally low.

Regional reservoir stocks decreased in all regions except north-west England where a small increase was recorded, while in the south-west, storage decreased by 11%. Storage is below average for the time of year in all regions, and in east England it is below the historic minimum for the end of September. For England as a whole, storage was 55%, which is 19% below the LTA for the time of year, and is lower than at the same time in 2025.

6. Forward look

October has had a relatively dry and warm start however the conditions are forecast to become more unsettled through the middle of the month, with low pressure in the north Atlantic bringing rain and showers. Rainfall will be most frequent in the north-west, with the south and east remaining drier. Later in October, the changeable weather pattern will continue bringing the wettest conditions again in the north-west.

For the 3-month period from October to December, conditions are more likely to be wetter than normal. The chances of a warm autumn and early winter are higher than normal however colder, drier spells can be expected especially in the latter part of the period.

7. Projections for river flows at key sites

By the end of March 2027, river flows have the highest chance of being below normal or lower across almost all of England especially in east and central England.

By the end of September 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.

8. Projections for groundwater levels in key aquifers

By the end of March 2027, groundwater levels in central England have a higher than average chance of being normal. Across the rest of England, particularly at sites in south-east, north-east, and east England, groundwater levels are projected to have the highest chance of being below normal for the time of year.

By the end of September 2027, groundwater levels across all of England are projected to be below normal or lower especially at sites in south-east, north east and east England.

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.