Friday
A plume of hot and humid air extends northwards across Britain. Plenty of sunshine overall, although high cloud will tend to build from the west and south. A risk of bursts of rain developing later in the day, moving up from the English Channel into southeast England, also moving across Ireland into western Britain later, but all very hit and miss. Southwestern coasts may see fog roll in from the Atlantic. A gusty southeasterly breeze. Highs 25 to 32C, hottest in the Home counties.

Friday night
Sporadic areas of rain and localised thunderstorms will track northeastwards overnight - the greatest risk of lively thunderstorms focused on East Anglia and Kent, before these move off into the North Sea. Scattered bursts of rain associated with a cold front move across northern Britain, introducing fresher air from the west. Central and southern areas stay very warm and humid overnight. Minimum temperatures 10 to 13C north & west, 15 to 19C Midlands, south and east.

Saturday
Local bursts of rain in the northeast will soon be away into the North Sea early morning. A scattering of showers spread from the west, perhaps frequent for a time in the morning for Wales and western England. These will tend to fizzle out, but local showers will drift eastwards through the middle of the day, and the odd heavy one reaching eastern counties by afternoon. Broken cloud and sunshine. A light to moderate westerly breeze. Feeling fresher, 18 to 25C, warmest southeast.

Sunday
A westerly airflow across Britain and Ireland will see a scattering of showers spread eastwards during the day - these most frequent in western areas in the morning, whilst by afternoon, some heavy ones are possible in east & northeastern regions, locally thundery in eastern Scotland. Drier overall in the south and southeast of England with sunny spells. Rain returns to the southwest later and into the night. Highs 17 to 23C.