The Met Office has warned that overnight heat will keep homes very warm as 'high humidities' make conditions feel worse during the current UK heatwave. Record temperatures have been hit and red alert warnings have been issued, with forecasters noting that this heatwave feels worse than some previous ones due to 'somewhat different' conditions.
Overnight Heat a Key Concern
Met Office forecaster Aiden McGivern said on the Met Office YouTube channel that the overnight impact can be significant because temperatures are staying elevated after dark. “It's not just the daytime temperatures to be concerned about,” he said. “It's those overnight temperatures, meaning that overnight buildings and homes won't get a chance to cool down.”
McGivern added: “Likewise, we won't be able to cool down so much because of the high humidities.” The humidity changes how the heat feels in the UK, particularly compared to previous notable hot spells. He said: “It feels somewhat different, especially when you take into account the humidity,” adding that, “in many ways the heat index is much higher”.
Heat Index and Cumulative Effects
He explained that the Met Office focus is not only on the numbers on the thermometer. “It's the heat index that we're most concerned about,” McGivern said. “It's that level of heat and humidity combined that can cause so many severe impacts.”
With several consecutive days of high temperatures, the meteorologist stressed the knock-on effect for people trying to sleep and for homes retaining heat. He said: "It's because of the day-by-day cumulative effects of the heat that these buildings are going to stay so warm".
Temperatures have been soaring this week due to a 'heat-dome' settling over western Europe, which has brought extreme conditions across the continent and the UK. The hottest temperatures are expected for Wednesday and Thursday with red Met Office warnings in place; however, the national weather agency has added another amber warning for Friday.
Impacts on Health and Infrastructure
A combination of extreme heat and humidity could have an impact on public health, infrastructure, power and water supplies, the Met Office said, and could cause heat-related issues for a range of sectors such as transport, energy and water supply. There could also be an increase in water safety incidents during the heatwave, the agency said, as more people are likely to visit coastal areas, lakes or rivers.
