Research and analysis

Yorkshire water situation: December 2025 summary

Updated 14 January 2026

Applies to England

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

1. Summary

This month, the rainfall in Yorkshire was above average and mostly fell in first 18 days. The soils remained fully saturated throughout the month. River flows in the Pennine-fed catchments ranged between normal to notably high, whereas those in the east were greater and ranged from notably to exceptionally high. Groundwater levels rose in all aquifers and reservoir stocks remained close to capacity.

2. Rainfall

All catchments recorded above average rainfall for December, which ranged between 100% to 144% of the long term average (LTA). Catchments across the Pennine ridge received rainfall within normal range and those to the south and east recorded above normal status. In the Derwent, Don and Hull catchments it was the second wettest November to December period and it was the third wettest November to December period in the Ouse in a 154-year record. Most of the rain fell within the first 18 days, with very little rain recorded from day 22 onwards. Days 14 to 18 were particularly wet in the Ouse, Rye, Derwent and Esk catchments.

3. Soil moisture deficit and recharge

Soils remained fully saturated for all weeks in December with very little variation between weeks.

4. River flows

Monthly mean flows in the Pennine catchments were above the LTA, between 115% and 162% of the LTA value, and classed between normal to notably high. Further east, catchments recorded greater monthly mean flows relative to their LTAs, ranging from 168% in the Esk, 189% in the Derwent to192% in the Rye. In the upper Hull catchment, monthly mean flows in the West Beck at Wansford Snakeholm Lock were 270% of the LTA. The monthly mean flows were classified as notably high in the Esk and exceptionally high in the Rye, Derwent and upper Hull.

Rivers in the Pennine-fed catchments and the Esk in the north-east started the month in an elevated state, most reported daily mean flows in the notably to exceptionally high range. They then continued for the next 11 days to fluctuate between exceptionally high to above normal and only the Ure, Wharfe and Calder recorded a short period when flows were normal. From day 13 to 15 flows receded temporarily to within normal range. By day 15 to 19 flows increased to either above normal or notably high in response to rainfall. Flows in these catchments then receded and by day 20 to 24 were classified as normal. Flows continued to decline to below normal starting on day 25 in the Ure, Wharfe and Aire followed by the remaining Dales catchments and the Calder later in the month. The Ure, Wharfe and Aire reached notably low for the time of year by the month end, whereas flows in the Don and Esk remained in normal range.

Flows in the east of Yorkshire area reflected ongoing effects of high November rainfall, further heavy rainfall in early December and from day 14 to 18, together with greater baseflow support from groundwater sources in these catchments. In the Rye and Derwent daily mean flows were notably or exceptionally high for much of the first three weeks of December, gradually receding from day 22 onwards and returning to normal for the time of year by the final week.

In the West Beck in the upper Hull, flows increased steeply from above normal to exceptionally high in the first two weeks of the month in response to rising Chalk groundwater levels. Flows continued to rise more gradually, then levelled off and declined slightly from day 26 onwards, again following the groundwater level trend. Nevertheless, the flows remained elevated and exceptionally high at month end. 

5. Groundwater levels   

5.1 Magnesian Limestone

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

5.2 Millstone Grit

The groundwater level within the Millstone Grit increased at Hill Top Farm and was normal for the time of year. It should be noted that this observation borehole is used for water abstraction by means of a pump. Therefore, the groundwater level recorded here may be subject to the effects of this.

5.3 Sherwood Sandstone

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

5.4 Corallian Limestone

The groundwater level within the Corallian Limestone decreased at Sproxton and was above normal for the time of year. At Malton, rising groundwater levels caused groundwater to emerge at the surface around 19 or 20 December, resulting in localised flooding in parts of the town. This is a known occurrence during times of high groundwater levels here and pumps were put in place ahead of the flooding to manage it. Pumping operations ceased during the final week of the month.

5.5 Chalk

The groundwater level increased steeply at Wetwang and was exceptionally high for the time of year. The groundwater level also increased steeply at Dalton Estate Well and was notably high for the time of year.

5.6 Reservoir stocks

Yorkshire reservoirs remained close to capacity throughout the month, with total stocks increasing by 5% between 1 December and 29 December. In the last week of December the reservoir total stocks were 92.4% of capacity, which was 2.7% above the long term average. 

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 herein.