Today could be a record-breaking day, with the all-time UK temperature record under threat. There is also the risk of thunderstorms, which will continue into tomorrow as the heatwave draws to a close.
The all-time UK temperature record is under threat today. 38.5c is the current record, set in 2003.
Overnight, some of the forecasting models have backed down a little in terms of maximum temperatures, thanks in part to cloud cover as some showers and thunderstorms develop this afternoon. But even so, we have a very hot day to come, with a very real possibility of the record being broken with temperatures peaking at around 39c.
You can keep track of the latest top-twenty of temperatures for the day here. And for a wider map of the temperatures across the UK and Ireland, take a look at the map of the current conditions here.
The heat will peak today, with cooler temperatures pushing in from the west into tomorrow.
As the transition begins, the atmosphere is going to become less stable, which, along with the heat today will trigger some thunderstorms and downpours. These are likely to push up from the south later into central southern England, before heading northeast. Some very strong thunderstorms are possible with frequent lightning, hail, gusting winds and torrential rain - but not all will catch one by any means.
Away from the main storm and shower risk area, for many it'll be a dry day with sunny intervals. There will be some showers affecting Ireland at times though. The east and south of England will be hottest with maxes into the low-mid thirties very widely. Elsewhere 25-30c will be typical with just Ireland in the cooler air, for now, with maxes of 20-23c.
This evening and overnight, a good scattering of thunderstorms will continue to rumble on - with northeast England and perhaps southeast Scotland seeing the bulk of them at this point. It'll be another very warm night too, especially in the east with temperatures in London perhaps not falling below 24c.
Friday will see further thundery rain and thunderstorms developing in central and eastern regions as the cold front bringing the transition to cooler temperatures moves across the country.
That'll mean fresher, cooler air arriving from the west but eastern parts will still have some heat with maxes into the high-twenties, perhaps low-thirties locally. The heat will slowly be squeezed away from the west through the day though, so away from the far east, temperatures will reach their maximum early before dropping back.
The weekend sees that thundery rain really struggle to clear eastern and northern Britain. So here, there will be the threat of some heavy rain right through Saturday and into the start of Sunday before it starts to clear from the south. Further southwest, it's a drier, brighter and fresher weekend in prospect with some long sunny spells and a scattering of showers.