A new scorching London heatwave is set to strike from this weekend, with a warning that the 34C highs already forecast for Tuesday (June 23) could actually end up being considerably hotter by the time we get there. Amber heat health alerts have been announced for London as well as the east, South East and South West of England to run until 8pm on Tuesday (June 23).
Forecast Details
Experts at both the BBC and Met Office are forecasting the official heatwave to begin in London from Sunday (June 21) when it is set to be 29C. The BBC is then predicting a further seven days in a row where it will be 30C or higher. There is a 40 per cent chance of exceeding the highest ever temperature for June, which is 35.6C set in 1957 and 1976, the Met Office said.
These temperatures are "pretty unusual even for the middle part of June", Met Office meteorologist Alex Deakin said. The next date London is set to experience temperatures below 30C is on Monday, June 29 when the BBC is forecasting 27C and light rain showers.
Humidity and Cloud Cover
But the hot spell may not bring the "wall-to-wall sunshine and blue skies" of the May heatwave, deputy chief forecaster, Gregory Wolverson, said. Cloud and fairly high humidity could make it feel "rather oppressive at times", he added.
Previous Heatwave Records
Temperature records were repeatedly broken during the May heatwave with 35.1C measured at Kew Gardens and 32.9C at Cardiff's Bute Park. There were 15 deaths in open water across the UK during May's hot weather.
Health Warning
The UK Health Security Agency (UKHSA)'s amber health warning means an "increased demand" is likely to be placed on health and social care services, and could result in a rise in deaths. Those aged 65 and over, as well as those with health conditions, will be most vulnerable, it said, though there may also be impacts on younger age groups.
London Heatwave Forecast in Full
BBC Weather experts are forecasting the London heatwave to last for eight days in their latest forecast for the next 14 days. It is set to end on Monday, June 29.
- Friday, June 19 - 30C sunny with a gentle breeze
- Saturday, June 20 - 27C sunny intervals with light cloud
- Sunday, June 21 - 29C sunshine. Start of heatwave
- Monday, June 22 - 32C sunshine
- Tuesday, June 23 - 34C sunshine
- Wednesday, June 24 - 32C sunshine
- Thursday, June 25 - 31C sunshine
- Friday, June 26 - 31C sunshine
- Saturday, June 27 - 32C sunshine
- Sunday, June 28 - 30C sunshine
- Monday, June 29 - 27C light rain showers. End of heatwave
- Tuesday, June 30 - 25C drizzle
- Wednesday, July 1 - 25C drizzle
- Thursday, July 2 - 23C drizzle
Rules for Heatwave Declaration
In the UK, a heatwave is officially declared when a location records at least three consecutive days with temperatures meeting or exceeding the temperature threshold. This threshold varies by county, reflecting the diverse climate across the UK. In London, temperatures need to hit at least 28C for three days. The latest BBC Weather forecast has temperatures surpassing this for eight days in a row. In the surrounding counties, temperatures must reach 27C for the same period of time.
