The United Kingdom is bracing for the final day of an extended heatwave, with forecasts indicating a shift towards cooler weather accompanied by the risk of thunderstorms and flash flooding. This period of high temperatures and low rainfall has been one of the driest and hottest on record for the UK.

Forecast models suggest that the dry and hot weather is likely to persist through August, impacting the potential for hosepipe bans currently affecting over 20 million people in England and Wales. Some locations, such as Wisley in Surrey, have recorded 47 consecutive days without measurable rainfall. Many other areas have experienced significantly less rainfall than usual in June and July.

While further heat spikes are possible as August progresses, the intensity of extreme temperatures, such as those reaching the high 30s Celsius, is expected to lessen as the sun's intensity diminishes. However, spells of heat reaching 30C or higher can still occur into September.

Southern and eastern England are expected to experience conditions meeting heatwave criteria on Tuesday. A heat map of the United Kingdom for Tuesday coloured in orange, yellow and red with top temperatures show in numbers for some major cities. The highest is 32C in Norwich. However, a change in weather patterns is anticipated, bringing cooler temperatures. The transition from prolonged dry conditions to potential heavy rainfall brings the threat of thunderstorms and subsequent flash floods, as indicated by weather forecasts.

This shift marks a significant change after a period where large parts of the UK have grappled with drought conditions. Side-by-side satellite images of north Wales and Merseyside, the left image is very green and the right is mostly brown The juxtaposition of extreme heat and drought with the sudden risk of severe storms highlights the volatile nature of the UK's current weather patterns. A white bolt of lightning lights up a dark purple, cloudy sky with silhouettes of trees in the foreground.