A yellow warning for thunderstorms has been issued by the Met Office for this weekend.
The widespread warning covers the entirety of Brecon and Radnorshire, most of Wales, and large parts of England.
The warning is in place for 10 hours - starting at 12 midday on Sunday and ending at 10pm the same evening.
The forecaster warns of heavy showers and thunderstorms, which could lead to some disruption in places, especially to travel.
It comes after two days of higher temperatures across the UK
Highs of 25°C are possible today (Friday) which could reach up to 26°C in the south on Saturday and Sunday, the Met Office says.
But this looks set to change as a band of low pressure moves towards the UK on Sunday.