Research and analysis

Yorkshire water situation: May 2026 summary

Updated 11 June 2026

Applies to England

• Publication for Northern Ireland
• Publication for Scotland
• Publication for Wales

Rainfall totals in Yorkshire in May were normal for the time of year. Monthly mean flows were below the long term average (LTA) and declining by the month’s end. Soils reacted to the rainfall pattern but became drier overall. Reservoir stocks decreased and were just below the LTA. Groundwater levels decreased in all aquifers and Hands off Flow (HoF) restrictions were put in place on abstractions in some river catchments.

1. Rainfall

April error correction: The April catchment average rainfall for the Hull was reported last month to be 60% of the LTA and within the normal range. This has been corrected to 26% of the LTA, classed as notably low. The resulting 12-month cumulative rainfall total is classed as normal. The Calder catchment average rainfall for April has been corrected to 57% of the LTA, in the below normal range.

Catchment average rainfall in May was normal with all catchments experiencing just slightly over the LTA for May. The exception was the Hull catchment which had slightly less rainfall than the LTA. The 3-month March to May rainfall totals were normal in the north-west catchments of Yorkshire, below normal in most central and eastern areas together with the Don in the south, and notably low in the Hull catchment in the south-east.

Much of the month was dry in the Hull catchment which just received small amounts of rainfall on days 2, 12 to 14 and 18.

Across the rest of Yorkshire most catchments showed a similar pattern with the wettest days on day 2, 18 and 19. There were locally wet conditions in the Don catchment on days 12 to 13. Scattered rainfall occurred from days 8 to 20 and beyond this, days were mostly dry.

2. Soil moisture deficit and recharge

Soils began the month dry in the Hull and Humber and lower Ouse region, wet in the northern Pennines and normal elsewhere. By the third week, rain caused the western Pennine soils to become near fully saturated while the Hull and Humber and lower Ouse region remained dry. By month’s end soils everywhere but the western Pennines were dry, and the Selby, Goole and lower Foulness area was very dry.

3. River flows

Monthly mean flows in May were normal or below normal in all catchments, ranging from 48% of the LTA to 73% of the LTA. Catchments with below normal flows mostly matched those in the east and south of Yorkshire that recorded less than normal 3-month rainfall during March to May.

Daily mean flows in the northern Pennine catchments began the month below normal or normal for the time of year. The rainfall on day 2 had a small impact, but most rivers remained within the normal range. The accumulation of rainfall from day 8 to day 20 had more of an effect and rivers peaked to above normal and notably high flows around days 19 and 20. Flows then gradually receded and most ended the month in the normal or below normal range.

In the Don and Rother flows were below normal and notably low for the time of year respectively at the start of the month. They responded to the rainfall on day 2 and the Don became notably high for the time of year. They also peaked on days 13 and 19 before declining until the month’s end, the Rother reaching exceptionally low flows for May.

Daily mean flows were below normal for much of the month in the Rye, Derwent and Ouse and for just under half of the month in the Esk. Rainfall resulted in a short period of above normal flows on days 19 and 20.

Flows in the chalk-fed West Beck declined steadily over the course of the month, beginning the month normal and ending the month below normal for the time of year. They also had a minor response to the rainfall on days 19 and 20.

4. Groundwater levels   

4.1 Magnesian Limestone

The groundwater level within the Magnesian Limestone decreased at Brick House Farm and was above normal for the time of year.

4.2 Millstone Grit

The groundwater level within the Millstone Grit decreased at Hill Top Farm and was notably low for the time of year. The groundwater level at this observation borehole may be affected by its use for water abstraction by means of a pump.

4.3 Sherwood Sandstone

The groundwater level within the Sherwood Sandstone decreased at Great Ouseburn and was above normal for the time of year. The groundwater level decreased at Riccall Approach Farm and was normal for the time of year.

4.4 Corallian Limestone

The groundwater level within the Corallian Limestone decreased at Sproxton and was normal for the time of year.

4.5 Chalk

The groundwater level decreased at Wetwang and was below normal for the time of year. The groundwater level decreased at Dalton Estate Well and was normal for the time of year.

5. Reservoir stocks

Reservoir stocks continued to decline at an average rate of around 1.5% per week. They had a slight increase in the third week of the month in response to the rainfall. At the end of May stocks were at 84.1%, 1% less than the LTA.

6. Environmental impact 

At the end of May, there were 21 abstraction licences with a HoF condition in force, and another 34 licence holders had been given advance warning that flows were low.

Author: Environment Agency, hydrology.northeast@environment-agency.gov.uk

Contact Details: 020 847 48174

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.