The Met Office has warned that temperatures could soar to 35C on Wednesday as a fourth heatwave hits the UK. Weather maps show up to 20 counties may see highs of 30C or above.
Tuesday will bring increasingly hot conditions, particularly across south-east England, where temperatures are expected to reach 29C or 30C before peaking on Wednesday.
Peak temperatures and heatwave criteria
A Met Office forecast map for 4pm on Wednesday indicates scorching highs of 34C in Cambridge and parts of Norfolk and Suffolk, along with 33C in London and parts of the Home Counties.
The high temperatures are likely to meet or exceed the local thresholds needed for the UK to record its fourth heatwave of the year. So far, 2026 has seen three defined heatwaves, in May, June and July.
Heat-health alerts issued
Amber heat-health alerts have been issued by the UK Health Security Agency (UKHSA) for the South East and London, the East Midlands and East of England. An amber alert means "significant impacts are likely across health and social care services due to the high temperatures, including a rise in deaths, particularly among those aged 65 and over or with health conditions," the UKHSA warned.
Yellow heat-health alerts have been issued for the South West, West Midlands and Yorkshire and the Humber. The alerts will be in place from 9am on Wednesday, July 29, until 9am on Thursday, July 30. No alerts are currently in place for the North East or North West of England, Wales, Scotland or Northern Ireland.
Counties forecast to reach 30C or above
The following counties are expected to see 30C or more on Wednesday: Bedfordshire, Berkshire, Buckinghamshire, Cambridgeshire, Essex, Greater London, Hampshire, Hertfordshire, Kent, Leicestershire, Lincolnshire, Norfolk, Northamptonshire, Oxfordshire, Rutland, Suffolk, Surrey, Warwickshire, Wiltshire, Worcestershire.
Met Office forecaster comment
Gregory Wolverson, deputy chief forecaster at the Met Office, said: "This is a short-lived spell of heat, but temperatures will climb quickly through the first half of the week, particularly in the southeast. By Wednesday, some areas could see temperatures in the mid-30s, and while the heat will not be widespread across the whole of the UK, it will be enough for parts of the southeast to likely meet official heatwave criteria by Thursday."
"Elsewhere, the weather will be more changeable, and the change to cooler, more unsettled conditions will arrive sooner from the north and west, with a mix of sunshine and showers. Across northern areas, it is possible there will be heavier showers with a small risk of isolated thunderstorms through the week."
