The Met Office has issued a severe weather warning for rain across much of southern England today, Thursday 15 January 2026, with forecasters predicting that some areas could receive more than half their typical January rainfall in a matter of hours.
Widespread Disruption and Flooding Fears
A band of low pressure is expected to move eastwards, bringing persistent and heavy downpours that will be at their most intense during the late afternoon. The official yellow warning for rain remains in place until 10pm, covering a vast swathe of the country including London, Kent, Surrey, East Sussex, West Sussex, Hampshire, and parts of the Midlands like Warwickshire and Oxfordshire.
Meteorologists are particularly concerned about surface water flooding due to already saturated ground from recent wet weather. The Environment Agency has already activated several flood warnings and alerts, including three along the River Severn in Gloucestershire and Worcestershire. Additional alerts are in force on the outskirts of London for rivers like the Mole in Surrey and the Wid and Can in Essex.
Staggering Rainfall Totals Forecast
The forecast indicates accumulations of 20-30mm widely, with the potential for 40-50mm in isolated spots. To put this into perspective, Brighton, which usually sees around 75mm of rain in an average January, could witness up to 50mm today alone. Similarly, Southampton, with a monthly average of 90mm, is braced for around half that amount this afternoon.
The Met Office stated on its website: "Given the saturated ground, this may lead to some surface water flooding." This follows 15mm of rain recorded on Tuesday in Port Ellen, Argyll and Bute, and widespread showers on Wednesday night.
How to Prepare for Potential Flooding
Residents in the affected regions are being urged to prepare an emergency kit in case of flooding. This kit should include:
- Important insurance documents and a list of key contact numbers.
- A torch with spare batteries.
- Any essential prescription medicines.
- Other vital supplies to sustain your household if you become cut off.
The unsettled conditions are set to continue into the weekend. The Met Office outlook suggests that Friday will see wind and rain clearing to the northeast, followed by sunshine and showers. Saturday is likely to be showery, with drier conditions expected on Sunday. Temperatures will be around average for the time of year, with overnight fog possible in some areas.
