Temperatures could reach 30C in bank holiday weekend heatwave

Temperatures could reach 30C in bank holiday weekend heatwaveImage source, EPA/ShutterstockBySarah Keith-LucasLead Weather PresenterPublished20 May 2026, 11:45 BST1 CommentsUpdated 39 minutes agoTemperatures are forecast to rise as high as 30C in parts of the UK as a potential heatwave develops across the long bank holiday weekend. Heat health alerts, external have been issued by the UK Health Security Agency (UKHSA) across much of the Midlands and south-east England valid from 09:00 Friday 22 May until 17:00 Wednesday 27 May.The mercury is set to creep up each day for the remainder of the week before the warmest weather of the year so far settles in. If readings reach 30C before Monday, it will be the earliest date this has happened in the UK for over 70 years. Image source, Yui Mok/PA WireImage caption, The warmest day of 2026 so far was back on 8 April where temperatures in London reached an unseasonably high 26.6CWhere will there be a heatwave and how long will it last?A heatwave in the UK is defined by the Met Office as at least three consecutive days with daily maximum temperatures exceeding a county-specific threshold, reflecting a sustained spell of unusually hot weather.The heatwave threshold temperature varies across the UK. In Greater London it is 28C whereas in Northern Ireland and Scotland it is 25C.It is likely that a few places could meet the heatwave definition during Friday, Saturday and Sunday. At the moment, areas such as London and the south Midlands are most likely to see this. With the unseasonable warmth expected to continue into Tuesday and beyond, more parts of England and Wales could experience a heatwave after the bank holiday weekend.Image caption, Maximum temperatures forecast for Saturday to MondayEven in places where a heatwave isn't likely, it still looks warm over the long weekend, with temperatures for most between 20-26C. As early as Friday afternoon, temperatures are expected to reach up to 28C in south-east England.This will...