The Met Office has expanded its heat dome warning as the UK is forecast to reach 38C this week, with a 25% chance of temperatures exceeding 40C. The warning now runs through the hottest stretch from Monday until Thursday, with the peak expected on Wednesday and Thursday.
Tom Crabtree, the Met Office deputy chief forecaster, said: "The forecast heatwave is developing into an impactful severe weather event, with record-breaking June temperatures and very high humidity". He added: "The combination of heat and humidity will be oppressive and bring impacts across society from public health and infrastructure, to power and water supplies."
Met Office warning areas
Monday and Tuesday's warning covers most of southern England, central and eastern Wales, and much of the Midlands. By Wednesday and Thursday, temperatures are expected to climb to 38C, while Friday should bring a drop to 33C across eastern areas. The UK Health Security Agency has issued yellow and amber heat health alerts alongside the weather warning.
Becky Mitchell on 37C
Becky Mitchell, a Met Office meteorologist, said: "We could also see three consecutive days with temperatures of 37C or above for the first time. That’s extraordinary in June." She also said: "Climate change is definitely playing a role in these temperatures. What happened in 2022 could happen again this week."
The forecast also points to very high overnight temperatures, with widespread tropical nights across southern parts of England and especially in urban areas. Mitchell said: "We could also break the June record for overnight minimum temperature, which doesn’t sound as exciting but can be quite impactful."
UK heat and humidity
The hot, humid and still weather conditions are also expected to bring a surge in mosquito numbers, particularly in the south of England away from coastal areas. Dan Pydynowski, a senior meteorologist at AccuWeather, said: "We are expecting a high number of mosquitoes over the next week or so, and that is certainly related to the upcoming weather conditions."
He added: "During periods of more intense heat, mosquitoes might rest in shady spots like tall grass during midday and will be most active at dawn and dusk." For people already affected by the warning, the most pressing issue is the stretch from Monday through Thursday, when high temperatures and humidity are expected to overlap for several days.
Record June temperatures
The Met Office said England's warmest June on record was in 2025, and the UK's second warmest June was also in 2025. The hottest recorded June temperature is 35.6C, set in Southampton in 1976 and in Camden Square, London, in June 1957. Against that record, the forecast puts the current heat dome within reach of new June extremes, while the monthly average temperatures have been steadily increasing since 1976.
