A prolonged heatwave is set to grip London starting this weekend, with the Met Office forecasting temperatures above 30°C and a yellow heat health alert extended through July 11. The UK Health Security Agency (UKHSA) issued the alert for London from noon on Saturday, July 6, until 8pm on Saturday, July 11, warning of increased health risks, especially for vulnerable individuals.
Temperature Forecast and Duration
Temperatures in London are expected to reach 28°C on Saturday, climb to 32°C on Monday, and remain between 28°C and 32°C for seven consecutive days, according to Met Office predictions as of 6:30am Saturday. A heatwave in London is defined as at least three consecutive days with maximum temperatures of 28°C or above. This spell follows a record-breaking June heatwave, when temperatures hit 37.7°C in Norfolk on June 26, the hottest June day on record.
Comparison to June Heatwave
Forecasters note that this heatwave may be more manageable than the previous one due to westerly winds keeping humidity lower and temperatures below June's extremes. High pressure positioned further west is expected to bring dry conditions to southern and central areas, with temperatures in the high 20s and potentially topping 30°C in parts of the South East. The June heatwave, which also affected much of mainland Europe, was deemed virtually impossible 50 years ago by scientists.
Climate Change Context
An analysis by the World Weather Attribution group found that a similar heatwave in the climate of 1976 would have been 3.5°C cooler, with lower daytime peaks and overnight temperatures. Professor Stephen Belcher, Met Office chief scientist, stated: "Human induced climate change has made events like this more likely and more intense. To see temperatures like this in the UK in June is sobering." He highlighted implications for health, transport, energy, and water supply.
Health and Public Advice
The yellow heat health alert advises the public to take precautions, particularly those with underlying health conditions, the elderly, and young children. Londoners are encouraged to stay hydrated, avoid peak sun hours, and check on vulnerable neighbors. The extended alert underscores the need for preparedness as heatwaves become more frequent due to climate change.
