Research and analysis

Water situation: May 2026 summary

Updated 10 June 2026

Applies to England

May was the third dry month in a row, with most of the country receiving below average rainfall. England as a whole received 74% of the long term average (LTA) rainfall, and the Met Office also announced that it had been the warmest spring on record. Soil moisture deficits (SMDs) continued to increase throughout the country. This is due to the combination of the below average rainfall and it being the warmest spring on record for England, and by the end of May soils across most of England were drier than expected for the time of year. Monthly mean river flows decreased at all indicator sites, and the majority of sites were classed as normal or below normal. Groundwater levels were classed as normal or higher at most reported sites despite groundwater levels decreasing at most sites. Reservoir storage also declined during May, and is slightly below average for the time of year across all of England.

1. Rainfall

May was another dry month, with England receiving 42.3mm of rainfall which represents just 74% of the 1991 to 2020 LTA. More than four-fifths of hydrological areas received below average rainfall during May. The wettest hydrological area by percentage of LTA was the Seaham area in north-east England, which received 155% of the LTA (74.3mm). By contrast, the driest was the Roding hydrological area in south-east England which received 27% of the LTA (12.5mm).

Rainfall was classed as normal or lower in all but one hydrological area in May. More than half of hydrological areas were classed as normal and nearly a third classed as below normal for the time of year. Nearly a fifth of hydrological areas were classed as notably or exceptionally low, all predominantly found in east and south-east England.

The 3-month cumulative period rainfall was classed as either notably or exceptionally low across most of country, including all hydrological areas of east and south-east as well as large parts of central and south-west England. There were also some below normal and normal cumulative totals, predominantly in north-east England, and areas of above normal or higher rainfall in the north-west. The 6-month period was a much wetter picture across England, with exceptionally high rainfall totals across many of the south coast hydrological areas of the country and normal or higher rainfall totals were recorded for the rest of England. During the 12-month cumulative period, rainfall was classed as normal or higher for much of England, although south-west and north-west England were much wetter with notably or exceptionally high totals.

At a regional scale, rainfall totals for May were classed as notably low for east England and below normal for south-east England with both regions recording their third consecutive month of below average rainfall. All other regions were classed as normal for the time of year however both central and south-west England both recorded their third consecutive months of below average rainfall. England as a whole was classed as below normal which was also the third consecutive month of below average rainfall.

2. Soil moisture deficit

By the end of May, SMDs continued to increase throughout the country due to the combination of the below average rainfall and it being the warmest spring on record for England. Current deficits are smallest in the north-west while the largest deficits are found in east and south-east England.

At the end of May, soils were drier than average across England. Soils are much drier than would be expected across east, central, south-east and south-west England following 3 months of below average rainfall.

3. River flows

Monthly mean river flow decreased at all indicator sites in May. All sites were classed as normal or lower with just over a third of sites classed as normal and 28 sites, just over half of indicator sites, classed as below normal for the time of year. Five sites, all in south-west England, were classed as notably low. Three sites, 2 of which were in east England, the River Yare and the Ely Ouse and Heaton Mill on the River Till in north- east England were classed as exceptionally low.

With the exceptions of the Lune in north-west England, which was classed as normal, all regional index sites were classed as below normal for the time of year.

4. Groundwater levels   

At the end of May, groundwater levels had fallen at more than four-fifths of the indicator sites we report on with only 4 sites recording a rise in levels. All but 3 indicator sites were classed as normal or higher for the time of year. Thirteen sites, all of which were in chalk aquifers were classed as normal. Five sites recorded above normal levels, and 2 sites were classed as notably high. Three sites were classed as exceptionally high for the time of year, Coxmoor (Idle Torne Sandstone) and Weir Farm (Bridgnorth Sandstone), both of which are in central England and Priors Heyes (West Cheshire Permo-Triassic Sandstone) in north-west England. Wetwang (Hull and East Riding Chalk) and Woodyates (Dorset Stour Chalk) were classed as below normal for the time of year, and Jackaments Bottom (Burford Jurassic Limestone) remained classed as notably low.

All the major aquifer index sites, with the exception of Redlands Hall (Cam and Ely Ouse Chalk) in east England recorded a fall in levels at the end of May. Skirwith in the Carlisle Basin and Eden Valley Sandstone in north-west England was classed as normal for the time of year. Chilgrove (Chichester Chalk) and Stonor Park (South West Chilterns Chalk) both in the south-east, Dalton Estate (Hull and East Riding Chalk) in the north-east and Redlands in the east were all classed as normal for the time of year. Jackaments Bottom in the Burford Jurassic Limestone in south-east England, remained at notably low levels due to the ongoing dry conditions. Levels at Weir Farm in the Bridgnorth Sandstone in central England and Little Bucket (East Kent Stour Chalk) remained exceptionally high and above normal respectively despite falls in levels. 

Regional reservoir stocks decreased across England and storage for all regions is slightly below average for the time of year. For England as a whole, storage was 88.2% at the end of May, which is slightly below average for the time of year.

5. Forward look

Mid-June is expected to begin with a transition to more settled conditions across much of the UK, as high pressure becomes more influential. This will be most noticeable across southern and eastern areas, while the north-west may remain cloudier with some rain at times. Temperatures are expected to increase, with the potential for very warm or hot conditions, particularly across parts of England. Towards the end of June and into early July, settled conditions are likely to continue, with prolonged periods of dry weather across much of England. However, there is some uncertainty in the position of high pressure, and occasional showers or thunderstorms may develop, particularly in southern areas. Temperatures are likely to remain above average overall, with the potential for further hot spells.

For the 3‑month period from June to August, the UK is more likely to experience above-average temperatures, with an increased likelihood of hot spells and heatwave conditions. Rainfall is expected to be close to average overall, although there is a slightly increased chance of wetter conditions, with rainfall likely to occur as showery and unevenly distributed events rather than prolonged periods of widespread rain.

6. Projections for river flows at key sites

By the end of September 2026, river flows across England are most likely to be within the normal range at the majority of indicator sites. However, there remains some probability of below normal and notably low flows at some sites, particularly across the north-west, central and eastern England, while a small number of sites, mainly in the south and east, show some likelihood of above normal flows.

By the end of March 2027, river flows across England have the greatest chance of being normal for the time of year. A number of sites, particularly across northern, central and parts of western England, retain some risk of below normal and notably low flows, while sites in the south and east show the greatest likelihood of above normal flows, with some indication also present in other regions.

7. Projections for groundwater levels in key aquifers

By the end of September 2026, groundwater levels across England have the greatest likelihood of being normal at the majority of sites. A number of sites, particularly across the south, east and parts of the Midlands, show an elevated probability of below normal and notably low levels, while some sites in the south and east also indicate a likelihood of above normal levels.

By the end of March 2027, groundwater levels across England have the greatest likelihood of being normal at the majority of sites. A number of sites, particularly across the south, east and parts of central England, show an elevated probability of below-normal and notably low levels, while many sites across southern, central and eastern England also indicate a likelihood of above-normal or higher levels.

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.