Extreme heat red weather warning issued in parts of East Sussex

The Met Office has officially issued a rare Red Weather Warning for Extreme Heat covering parts of East Sussex.

The warning is in effect from 9:00 am on Wednesday, 24 June until 9:00 pm on Thursday, 25 June 2026. Forecasters warn of an exceptional spell of dangerously hot and humid weather, with maximum temperatures in the shade expected to exceed 37°C and potentially spike between 38°C and 40°C in certain areas. 

Affected Areas in Sussex

The highest-level red warning specifically impacts inland, northern, and eastern parts of the county, including: 

• Crawley
• Horsham
• Haywards Heath
• Uckfield
• Crowborough
• Billingshurst
• Petworth 

Note: Coastal areas like Brighton & Hove are currently under a slightly lower Amber Weather Warning, as coastal breezes are expected to keep temperatures marginally cooler. 

Key Risks & Expected Impacts

• Danger to Life: The Met Office explicitly states that adverse, population-wide health effects are highly likely. The risk of serious illness is not limited to vulnerable groups. 
• High Nighttime Humidity: Unlike previous UK heatwaves, this event will feature unusually high humidity levels (around 20–30%). Very warm nights will make it difficult for the body to cool down and recover. 
• Daily Disruption: Substantial changes to daily routines and working practices are required. Local business closures, amended hours, and cancelled fitness classes have already been announced across Sussex. 
• Infrastructure Strain: Expect significant disruption to road and rail travel, alongside severe pressure across healthcare and public services. 

Official Safety Advice

Local councils and health authorities advise taking immediate action to stay safe: 

1. Avoid Midday Sun: Stay out of direct sunlight between 11:00 am and 3:00 pm.
2. Hydrate Constantly: Drink plenty of water and avoid excessive alcohol or caffeine.
3. Keep Indoor Spaces Cool: Close curtains and windows on rooms facing the sun during the day.
4. Check Travel Updates: Carry extra water if you absolutely must travel, as rail delays due to track temperatures are possible.
5. Support Neighbors: Keep a close eye on isolated, elderly, or vulnerable family members and neighbors.