UK forecasts point to third heatwave of the summer

London could hit 31C by Monday, and southern and eastern England could reach the low 30s Celsius. The hot spell could become the third heatwave of the summer, and potentially the third within a month, with the hottest conditions most likely in southern, central and eastern areas.

A UK heatwave is at least three consecutive days when a location records daily maximum temperatures at or above its local threshold, which varies by county. The forecast is set to peak over the weekend before easing early next week, with the north and west likely to stay closer to average and more unsettled. Similar heat can build as high pressure moves in from the Atlantic or the Azores.

The Met Office and the UK Health Security Agency run the weather-health alerting system together, and a yellow Heat-Health Alert had been issued for parts of England during the recent hot spell. Heat is especially dangerous for older people and for people with heart, blood vessel and lung disease.

This latest forecast follows a brutal late-June stretch that brought a red heat-health alert in six regions of England, alongside an Amber extreme heat warning for much of southern England and southeastern Wales. That earlier warning covered the South West, South East, London, East of England, West Midlands and East Midlands. The new spell is different from the last one, with the hottest weather expected to arrive over the weekend rather than later in the week.