The Met Office has said that for most of England the temperature will remain up to the high 20s over the next few days, but some areas will see “thundery and unstable” conditions.
The weather will give way on Thursday and Friday in parts of North West and North Wales, Northern Ireland and parts of Scotland.
Met Office spokesman Stephen Dixon said most regions will see a drop in the temperature which is below the threshold for a heatwave.
Dixon said: “The dry, fine and sunny weather is to continue for the next few days with temperatures peaking at 30 degrees in parts of England.
“Temperatures remain above average for the time of year in the mid-to-high 20s (and) dropping below those heat wave thresholds in some counties.
“On Thursday there is a chance of thunder moving into western areas of Northern Ireland, the west of Scotland, North West England and North Wales.”