Nighttime temperatures will stay high across large parts of the country this week, with some locations not cooling below 20°C — so-called “tropical nights.”
Forecasters say Thursday night could bring the warmest June night on record, with minimum temperatures across Wales, the Midlands and the South East only dropping to around 21–23°C.
That would push some places above the existing UK and England nightly minimum record of 22.7°C from 1979, and could eclipse the Wales record of 20.3°C set just this week.
Apparent or “feels like” temperatures may be even higher: during the coolest hours it may still feel like around 27°C.
What makes this heatwave notably different from earlier ones is the persistence of warm nights. During the July 2022 hot spell many areas experienced tropical nights, but only rarely for more than two nights running.
This time some locations could see three or four consecutive tropical nights, which has much greater consequences. When nights stay warm, bodies don’t get a chance to cool down between hot days.
That lack of overnight relief increases risks for vulnerable people but can also affect otherwise healthy individuals — causing poor sleep, extra strain on the cardiovascular system and raising the chance of heat exhaustion as the heat persists.
Scientists warn that as the planet warms, heatwaves like this will become more frequent. Unless greenhouse gas emissions are reduced substantially, global warming is expected to continue and accelerate.
A warmer atmosphere can hold more moisture, so the combination of higher temperatures and humidity makes humid heatwaves more likely to be both common and intense in future.
