Live forecasts update automatically; written guidance last reviewed 16 June 2026 by the Public Report weather desk. Data from national met services via Open-Meteo.
Live data from Open-Meteo · updates automatically ·
A UK heatwave is declared when a location records three or more consecutive days with maximum temperatures meeting or exceeding a regional threshold (usually 25–28 °C). The Met Office issues heat-health alerts when these conditions pose a risk to vulnerable groups, typically from June to August.
What defines a heatwave in the UK?
The Met Office defines a heatwave as three or more consecutive days where the daily maximum temperature meets or exceeds a threshold that varies by UK county – 25 °C in most of England and Wales, 28 °C in London and the South East, and 22 °C in Scotland and Northern Ireland. During a heatwave uk 2025 event, these thresholds triggered Level 3 and Level 4 heat-health alerts across southern England. The official heatwave uk map, updated daily on the Met Office site, shows current exceedances by region.
How long does a UK heatwave last?
Most heatwaves persist for 4–9 days, but prolonged spells can reach 14–17 days, as seen during the heatwave uk 2022 record-breaking July. The question “how long is the uk heatwave going to last” is best answered by checking the live ranking above, which shows current warning duration. September heatwaves are rare but possible – the heatwave uk september 2023 event lasted 5 days in East Anglia. For the shortest outlook, see our 10 Day Weather Forecast UK.
When is the next heatwave in the UK?
The Met Office does not issue long-range forecasts for a specific heatwave uk 2025 date more than 10 days ahead. Check the Next Heatwave Uk page for the latest official outlook and the live ranking above.
Is the UK getting more heatwaves?
Yes. Climate projections show the frequency of heatwaves in the UK has increased since the 1990s. By the uk heatwave 2026 season, models suggest a 50 % chance of a 40 °C event in southern England every 10–20 years.
What should I do during a heatwave?
Stay hydrated, keep indoor spaces cool, check on elderly or vulnerable neighbours, and never leave children or pets in parked cars. The NHS recommends avoiding strenuous outdoor activity between 11am and 3pm.