It will be a different story for Scotland and Northern Ireland with outbreaks of heavy rain.
Some wet weather will also affect parts of northern England and Wales and temperatures here will reach around 17-24C (63-75F), closer to the seasonal average.
Saturday will be less hot overall but by Sunday and Monday temperatures will rise again, perhaps touching 32 or 33C (90-91F).
Sunny spells are likely but the heat may also spawn a few big thunderstorms.
There is uncertainty about the forecast into the middle of next week but many computer weather models allow heat to linger, especially in the south.
It is likely that some places will reach their official heatwave criteria – three consecutive days of temperatures above a threshold, which varies from 25 to 28C (77-82F) across different parts of the UK.
