Research and analysis

South-east England water situation report: January 2026 summary

Updated 17 February 2026

Applies to England

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

1. Summary

The year of 2026 started off rather wet across the South-east of England with 192% of the long term average (LTA) recorded. This was due to 3 named storms affecting the South-east, that of Storm Goretti on the 8 January, Ingrid on 24 January and Chandra on 26 January. Over half of the areal units were the wettest January since 2014 and many of those were second or third wettest January on their respective records. The soil moisture deficits (SMDs) fell during the month and were reduced to zero by the second week in most of the areal units across the South-east during January. They were well below the LTA for the end of January in each Area. Once the SMDs were close to zero within the first 2 weeks of the month, recharge continued at pace. By the end of January, the total winter recharge so far (October to January) was above average. The river flows were all normal or higher for January. Flows generally rose at all of the key indicator sites during the month, due to multiple peaks, reflecting the storms and bands of heavy rain that moved across the South-east during January. There was a total of 213 fluvial flood alerts and 43 fluvial flood warnings issued across the South-east. The groundwater levels across the South-east rose during January and significantly so at a number of sites. All of the key indicator sites were at normal levels or higher for the time of year. There were 8 groundwater flood alerts issued, mainly in Solent and South Downs (SSD), but also one in Thames (THM) by the end of the month

2. Rainfall

The year of 2026 started off rather wet across the South-east of England with 192% of the LTA recorded. This was due to 3 named storms affecting the South-east, that of Storm Goretti on the 8 January, Ingrid on 24 January and Chandra on 26 January. The first week was cold with an arctic air mass being the biggest influence on the weather and bringing some snow to parts of the South-east. Low pressure systems then dominated the rest of the month when temperatures rose compared to the first week, but remained slightly below average for the month. The highest daily rainfall total was 42.9mm recorded at Lyndhurst (Lymington, SSD) on 26 January but the wettest day was 8 January when there was widespread heavy rainfall across the whole of the South-east and accounted for, on average, 16% of the monthly total. The second wettest day was 15 January and third wettest day was 26 January. When all three days were combined, on average, around 40% of the monthly rainfall was recorded. The 8 January was the wettest in Hertfordshire and North London (HNL) and Kent and South London (KSL). SSD was wettest on 26 January, and THM had 4 fairly equally wet days being 8, 15, 21 and 26 January.

Over half of the areal units were the wettest January since 2014 and many of those were second or third wettest January on their respective records. Most of the South-east received rainfall in the exceptionally high category with the exception of a few areal units across the north of THM and HNL that received notably high rainfall for January. There were eight groundwater flood alerts issued, mainly in SSD, but also one in THM by the end of the month.

3. Soil moisture deficit and recharge

The SMDs fell during the month and were reduced to zero by the second week in most of the areal units across the South-east during January. They were well below the LTA for the end of January in each Area, with only KSL having a few remaining millimetres of SMD in Thanet and North West Grain areal units. Whilst recharge had begun last month despite the remaining SMDs, once the SMDs were close to zero within the first 2 weeks of the month, recharge continued at pace. By the end of January, the total winter recharge so far (October to January) was above average compared to the end of December when there had only been just above two-thirds of the winter recharge to the end of December. Each Area had above average recharge for January, although THM, KSL and SSD all recorded around twice the LTA for the end of January.

4. River flows

The river flows were all normal or higher for January. Flows generally rose at all of the key indicator sites during the month, due to multiple peaks, reflecting the storms and bands of heavy rain that moved across the South-east during January. The highest flows were on or around the Wealden Clay, mostly in KSL, but with a few exceptions being the Wey at Tilford (THM), the Rother at Iping Mill and Arun at Alfoldean (both SSD).  Lymington at Brockenhurst (SSD) responded significantly to Storm Chandra. Flows on the Wey at Tilford (THM), Arun at Alfoldean and Lymington at Brockenhurst (both SSD) all reached the second highest January flows on record, the highest since 2014. There was a total of 213 fluvial flood alerts and 43 fluvial flood warnings issued across the South-east.

5. Groundwater levels   

The groundwater levels across the South-east rose during January and significantly so at a number of sites. All of the key indicator sites were at normal levels or higher for the time of year compared to last month when there were still sites at below normal and lower. The key indicator sites where levels were highest were in SSD reflecting some of the highest rainfall totals during January and the impact of Storm Chandra in particular. Levels at Houndean Bottom (SSD) reached the fourth highest January on record after 2016 and Carisbrooke on the Isle of Wight (also SSD) ended the month at the third highest January on record, after 1995. The only key indicator site higher than normal that wasn’t in SSD was Rockley (THM) that ended the month at above normal levels. There were 8 groundwater flood alerts issued, mainly in SSD, but also one in THM by the end of the month.

6. Reservoir stocks

The reservoir storage remained below the LTA at Farmoor, Lower Thames (both THM) and at Arlington (KSL) and on the LTA at Bewl (KSL) and at the Lower Lee reservoirs (HNL). The storage at the remaining reservoirs at Bough Beech, Weir Wood, Darwell , Powdermill (all KSL) and at Ardingly (SSD) had recovered to above the LTA for January and were at 100% , with just the exception of Darwell.

Author: groundwaterhydrology@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.