South-east England water situation report: July 2026 summary
Updated 12 August 2026
Applies to England
© Crown copyright 2026
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1. Summary
July was a record breaking dry month with only 1% of the long term average (LTA) rainfall recorded across the south-east of England. There has been no significant rainfall recorded anywhere in the south-east since 9 June. For the whole of the south-east of England, Thames area (THM), Hertfordshire and North London (HNL), Solent and South Downs (SSD), Kent, South London and East Sussex (KSLES) and most of the hydrological areas, this month has been the driest July on record of 156 years. This has led to a ‘flash drought’ being declared across a large swathe of central, eastern, and southern England on 29 July. Most of the water companies that operate across the south-east issued temporary use bans (TUBs) during July as a result of the ongoing hot, dry conditions of the last couple of months.
The soil moisture deficits (SMDs) rose steadily through the month to end significantly above the LTA for July. The SMDs for SSD and THM ended the month about twice the LTA. Key indicator flow sites were spread from normal to exceptionally low during July. The expected steady decline of groundwater levels for this time of year continued during the month. All key indicator groundwater sites ended July at normal or below normal levels with the exception of Jackaments (THM) that ended the month at notably low levels.
1.1 Rainfall
July was a record breaking dry month with only 1% of the LTA rainfall recorded across the south-east of England. There has been no significant rainfall recorded anywhere in the south-east since 9 June. The highest daily total was 3mm recorded on 25 July at Clavering, (HNL). Most of the rainfall was recorded on the 25 July when there were light patchy showers. High pressure across the country has dominated the weather throughout July bringing dry, hot weather with further heat waves occurring and heat alerts and warnings being issued. There have now been 30 days where temperatures have been 30 degrees in 2026 so far. For the whole of the south-east of England, THM, HNL, SSD, KSLES and most of the hydrological areas, this month has been the driest July on record of 156 years. In addition, 11 of the 46 hydrological areas are recorded as being the driest 5-month period ending in July since 1976. This has led to a ‘flash drought’ being declared across a large swathe of central, eastern, and southern England on 29 July.
1.2 Soil moisture deficit and recharge
The SMDs rose steadily through the month to end significantly above the LTA for July. The SMD for SSD and THM ended the month about twice the LTA. The SMDs are now higher than for the same time last year and most hydrological areas are the highest on record or second highest after 1976. Despite very little recharge expected in July, there was zero calculated across the south-east bringing the total for the summer so far (April to July) to just 15% of the LTA.
1.3 River flows
Key indicator sites were spread from normal to exceptionally low flows during July. Eight of the 21 sites were normal and 5 sites were exceptionally low. Of those 5 sites, the River Arun at Alfodean (SSD) recorded the second lowest July flows on record since 1976. The River Coln at Bibury (THM) had the fourth lowest July flows but only the lowest since 2025. Lymington River at Brockenhurst (SSD) and the River Rother at Udiam (KSLES) also had the fourth lowest flows on record and lowest since 2022. The one remaining site that recorded exceptionally low flows was the River Thames at Kingston (THM) but is only the 23rd lowest July on its substantially longer record, but is the lowest since 2022.
Generally, all of the key indicator sites with normal flows were on Chalk that remain supported by the normal groundwater levels. No fluvial flood alerts or warnings were issued.
1.4 Groundwater levels
The expected steady decline of groundwater levels for this time of year continued during the month. All key indicator sites ended July at normal or below normal levels. There was one exception at Jackaments (Oolites, THM) that ended the month as the fourth lowest July level on record, but only since 2025 and was notably low. This is mainly due to the wetter than average winter providing rainfall and recharge until around April when the recharge period ended.
1.5 Reservoir stocks
The high temperatures and lack of rainfall has resulted in some significant declines in reservoir storage. All of the reservoirs recorded below LTA storage for July with just two exceptions being Weir Wood (KSLES) that ended the month above the LTA and Bough Beech (KSLES) that was average for the time of year.
Most of the water companies that operate across the south-east issued temporary use bans (TUBs) during July as a result of the ongoing hot, dry conditions of the last couple of months.
Author: HNL Groundwater and Hydrology, 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.