Yorkshire water situation: May 2025 summary
Updated 12 June 2025
Applies to England
© Crown copyright 2025
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1. Summary
For the first 23 days of May there was almost no rainfall, river flows reduced, soils continued to dry out and reservoir stocks decreased to record low levels for the time of year. From day 23 there was enough rainfall to raise river flows temporarily and ease the rate of decline in reservoir stocks. However, this rainfall was not sufficient to reverse the general trend of below normal flows, dry soils, and declining groundwater levels caused by one of the driest late winter and springs on record.
2. Rainfall
May rainfall was divided between the first 22 days of May, which had almost no recorded rainfall, and a much wetter period from day 26 to 29. For the month as a whole, rainfall totals were normal or below normal for the time of year, ranging from 53% to 90% of the long term average (LTA). It was the third driest January to May since 1871, with only 1896 and 1929 having lower rainfall totals.
Until day 23 many of the rain gauges within Yorkshire recorded less than 2mm, the exceptions were the Rye and Esk catchments where small daily rainfall totals of up to 8mm occurred between day 3 to 5. From day 23 to the end of the month the weather was unsettled with monthly average rainfall totals in the Ure, Nidd, Wharfe and Aire catchments that reached the normal range. Elsewhere the rainfall amounts were below normal for the time of year.
The largest rainfall totals occurred over the highest Pennine catchments. At Beckermonds in upper Wharfedale there was no recorded rainfall for the first 22 days of May. This was followed by 88.6mm of rain between day 26 to 29, equivalent to 90% of the May LTA.
3. Soil moisture deficit
In general, soil moisture deficits continued to rise throughout May. In most catchments soils were dry at the start of the month and, with the exception of the Pennine Areas, became very dry by the end of the month. The driest soils occurred in the lower lying catchments of the Vale of York, the lower Ouse, the lower Don, and the Hull.
4. River flows
Monthly mean river flows for most Yorkshire catchments were between 31% and 76% of the LTA for May. River flows in the Ure were within normal range. Flows were below normal in the Wharfe and Rye and notably low in Swale, Nidd, Ouse, Aire, Don and West Beck. In the Calder, Rother and Derwent river flows were exceptionally low.
River flows across most Yorkshire catchments remained below normal to exceptionally low for the time of year until day 24. The only exception was at Hunsingore in the lower Nidd where flows increased to normal from day 19.
From day 26 to the end of the month the larger rainfall totals increased river flows in the Pennine catchments from the Don to the upper Swale to between normal and exceptionally high for the time of the year. In the Esk, Rye and Derwent the response was less marked with river flows only increasing to notably low or below normal.
Throughout May, flows in the chalk catchments of West Beck remained consistent and notably low for the time of year.
5. Groundwater levels
5.1 Magnesian Limestone
The groundwater level within the Magnesian Limestone at Brick House Farm decreased and remained at above normal for the time of year.
5.2 Millstone Grit
The groundwater level within the Millstone Grit at Hill Top Farm decreased and remained at notably low for the time year. This observation borehole is used for water abstraction by means of a pump which may affect the groundwater level recorded here.
5.3 Sherwood Sandstone
The groundwater level within the Sherwood Sandstone at Great Ouseburn decreased and remained at above normal for the time of year. The groundwater level also decreased at Riccall Approach Farm and remained at normal for the time of year.
5.4 Corallian Limestone
The groundwater level within the Corallian Limestone at Sproxton decreased and remained at below normal for the time of year.
5.5 Chalk
The groundwater level at Wetwang decreased and remained below normal for the time of year. The groundwater level also decreased at Dalton Estate Well and was below normal for the time of year.
6. Reservoir stocks
Reservoir stocks continued to decline at an average rate of 3% per week throughout the month and by the end of the month were 24% lower than the LTA.
7. Environmental impact
In late May there were 23 abstraction licences subject to a hands off flow (HOF) restriction. There were a number of reported environmental incidents related to low flows and dry weather. There were also impacts on the available water to support the Pennine canals.
Author: Environment Agency, hydrology.northeast@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.
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