38C Amber Heat Warning: UK Braces for Peak of Fifth Heatwave

A rare amber extreme heat warning from the UK Met Office came into force across a large stretch of England on Thursday, covering Eastern England, London and the south-east, the Midlands and parts of Yorkshire and Humber. The warning runs from 09:00 to 23:59 BST and marks the peak of the UK's fifth widespread heatwave of 2026, with mid-30s Celsius expected across the warning area and isolated spots potentially reaching 38C (100F).

Health Alerts Already in Place

Alongside the Met Office warning, amber heat health alerts issued by the UK Health Security Agency are already in force across the entirety of England until 21:00 BST on Friday 14 August. These alerts warn of significant impacts on health and social care services, including a rise in deaths, particularly among those aged 65 or over and people with pre-existing health conditions. Dehydration, heat exhaustion and the risk of power cuts, plus disruption to rail and air travel, are among the hazards highlighted by authorities.

Tropical Nights Adding to the Strain

Compounding the daytime heat, forecasters warn of so-called tropical nights across parts of the UK, where overnight temperatures fail to drop below 20C. As increasingly humid air pushes into western areas, the cumulative stress on the body from unrelenting heat day and night is expected to rise. The heatwave is nevertheless forecast to be short-lived, lasting only two or three days, with temperatures beginning to ease over the weekend — though even then they are expected to remain at or slightly above average for mid-August.

Records Set to Fall

According to BBC Weather presenter Helen Willetts, the coming days are likely to see long-standing temperature records broken. If temperatures reach 35C this week as forecast, it would make 2026 the first year in history to record 35C or above in four separate calendar months. Should the mercury hit 36C or higher, 2026 would also become the first year on record to register four separate days at or above that threshold, surpassing the previous joint record of three days shared by 1990, 2003, 2020 and 2026 itself. London and a handful of other locations could conceivably touch 38C — which would equal the highest temperature recorded in the UK this summer so far, set at Lingwood in Norfolk on 26 June. It would also tie for the hottest August day since 2003, when 38.5C was measured. As long as August temperatures remain at or above average overall, summer 2026 will replace 2025 as the warmest summer on record.