The Met Office has issued a rare red weather warning for Wednesday and Thursday, covering southern Wales and parts of England including London, as extreme heat and humidity pose a risk to life. The UK Health Security Agency has also issued a red heat health alert for six English regions, indicating danger even for healthy individuals.
The red warning area spans from Swansea in Wales across to Somerset, up to Birmingham, and east to southern Cambridgeshire, including London and inland Kent. Temperatures are expected to exceed 37C in the shade, potentially reaching 38-40C in some places, with high humidity exacerbating health risks. Night-time temperatures will remain high, limiting recovery.
This is only the second red heat health alert ever issued, following the July 2022 heatwave when temperatures surpassed 40C. An amber warning covers most of the rest of Wales, Cornwall, Yorkshire, and Lancashire. The Met Office warns of substantial disruption to travel, energy supplies, and potential property damage.
Experts have expressed alarm, with Professor Bill McGuire of University College London noting that temperatures above 43C are possible and that UK infrastructure is not built for such conditions. Professor Friederike Otto of Imperial College London called the situation a growing public health threat, urging urgent action. Some schools, such as Kingdown School in Warminster, have closed early this week to protect students.
