The United Kingdom recorded its warmest day of 2025 so far as temperatures soared to 29.4°C in Santon Downham, West Suffolk, on Friday, June 13, according to the Met Office. This narrowly surpassed the previous 2025 record of 29.3°C set on May 1 at Kew Gardens, west London. The heatwave, most pronounced in the South East, saw temperatures up to 10°C above the seasonal average, prompting an amber thunderstorm warning for East Anglia, eastern East Sussex, and Kent due to risks of torrential rain, large hail, frequent lightning, and gusty winds.
Record-Breaking Heat in the UK
On June 13, 2025, the UK experienced its hottest day of the year, with temperatures reaching 29.4°C in Santon Downham, West Suffolk. This figure just edged out the previous high for 2025, which was 29.3°C recorded on May 1 at Kew Gardens in west London. The Met Office confirmed that the South East was especially warm, with temperatures in some areas up to 10°C above the average expected for mid-June.
The Met Office typically expects maximum temperatures to be between 16–18°C in northern parts of the UK and 18–20°C in the south at this time of year. However, the recent heatwave has brought exceptional warmth, with Scotland also experiencing its hottest day of the year so far, as temperatures in Lossiemouth hit 25.7°C.
Regional Highlights and Comparisons
The heat was most intense in eastern and southeastern England, where some forecasts had predicted temperatures could reach as high as 30°C, potentially surpassing popular holiday destinations such as Ibiza, Mykonos, and even Los Angeles. In reality, Santon Downham’s 29.4°C was the official peak. For context, earlier in the year, parts of southern England had already recorded temperatures above 23°C, with Otterbourne in Hampshire reaching 23.7°C, making it warmer than Ibiza, Rhodes, and Cyprus at the time.
Weather Warnings and Thunderstorm Risk
The soaring temperatures and high humidity created conditions ripe for severe weather. The Met Office issued an amber thunderstorm warning for parts of East Anglia, eastern East Sussex, and Kent, effective from 8pm on Friday until 5am on Saturday. The warning highlighted the risk of torrential rain, large hail, frequent lightning, and gusty winds.
Additionally, a yellow thunderstorm warning was in place for London, the South East, South West, Wales, and the West Midlands from Friday afternoon until early Saturday morning. From midnight on Saturday, the warning expanded to include the East Midlands, North East England, North West England, South West Scotland, and Wales, remaining in effect until 6pm on Saturday.
Potential Impacts and Public Advice
Meteorologists warned that the combination of heat and humidity could spark “very severe weather” overnight, with torrential downpours potentially bringing 30–50mm of rain in some areas, and even greater accumulations if thunderstorms aligned. There was also a risk of surface water flooding, large hail, gusty winds, and frequent lightning, which could cause damage and power cuts.
Many places within the warning area may not see significant impacts, but those areas that do could experience rapid and intense rainfall, increasing the likelihood of localized flooding and travel disruption.
Historical and Seasonal Context
This year’s heatwave is notable not only for its intensity but also for its timing. The Met Office noted that such high temperatures are well above the average for mid-June, which is typically between 16–20°C. The previous all-time high for April, for example, was 29.4°C in London on April 16, 1949. The last time the UK saw temperatures above 27°C in April was in 2018 in Cambridge.
Earlier in 2025, March was the sunniest on record in England since 1910 and remarkably dry, with rainfall amounting to only 43% of the average. The highest temperature before this recent heatwave was 21.3°C, observed in Northolt, west London, and Chsey, Surrey, on March 20.
Looking Ahead
As the weekend progresses, temperatures are expected to decrease due to cooler air moving in from the north. The southern coast of England is likely to remain the warmest on Saturday, with a forecast high of 21°C, while Sunday’s temperatures are expected to peak around 17°C. However, the lingering risk of thunderstorms and unsettled weather will persist across much of the UK into the weekend.
