The Met Office says 35C temperatures ‘are possible’ in London early next week in the hottest period of the year so far. Currently highs of 34C are expected on both Monday and Tuesday (June 30 and July 1) amid a second heatwave of the month, but meteorologists say the mercury could even rise above this. But Tuesday could reach 35C, the Met Office have said.
Met Office Chief Meteorologist, Matthew Lenhert, says this is most likely on Tuesday where the South East of England is likely to be the warmest part of the UK. He said: “Overnight temperatures will remain high, with some locations not dropping below 20°C in what is called a tropical night. These sorts of temperatures make it hard to sleep and prevent any recovery from the high daytime temperatures too. Tuesday will be another hot day, though the highest temperatures will be more confined to the south east of England where 35°C is possible. Fresher air will move in from the west through the middle of the week, bringing an end to this heatwave.”
In London the mercury is not expected to drop below 22C, before temperatures ramp up again to either 34C or 35C on Tuesday. Weather experts say this can have a “profound impact on human health”, as the body relies on cooler nighttime conditions to regulate core temperature and recover from daytime heat.
Thankfully Tuesday will be the last day of extreme heat in London as fresher air will move in from the west by the middle of the week. Nonetheless, it will still be warm in the capital with temperatures gradually dropping from 28C on Wednesday to 24C on Sunday.
The World Weather Attribution says global warming is behind the trend of why June, usually considered the coolest of the summer months, is more prone to heatwaves. Prior to the industrial revolution a heatwave in June (where the temperature exceeded 28C for three consecutive years), was a one in 50 year event. They now take place every five years on average, with two occurring in June 2025 alone.
Forecast for London
Monday 30th
A very hot and sunny day is expected throughout Monday, with wall-to-wall sunshine and highs reaching 33°C, dipping to 20°C overnight. It will feel humid inland, though coastal areas may be slightly cooler with light onshore breezes. The evening will remain dry and mostly clear, with a very warm and muggy night to follow.
Tuesday 1st
Another dry and hot day, with temperatures again peaking at 33°C and falling to 18°C overnight. Sunny spells will dominate, though some patchy cloud may develop. There’s a small chance of isolated thunderstorms later. Winds remain light, and it will continue to feel very warm and humid.
Wednesday 2nd
A significant change in conditions. The day starts dry and partly cloudy, but by the afternoon it will become increasingly cloudy. Thunderstorms are likely to break out, bringing heavy downpours in places. Much cooler than earlier in the week, with a high of 25°C and a low of 15°C.
Thursday 3rd
Thursday will be cooler again, with a high of 22°C and a low of 12°C. The morning will be partly cloudy with some spells of rain, potentially thundery at times. However, it should dry out later in the day with some sunny intervals and widespread evening sunshine.
Friday 4th
The weather improves again, turning dry with widespread sunshine. It will feel pleasantly warm with a high of 25°C and a low of 14°C, and winds remain light.
Saturday 5th
Saturday looks to be mostly dry but more overcast than previous days, with a mix of cloud and some bright spells. Temperatures will be slightly cooler, with a high of 23°C and a low of 16°C.
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