Monday
Patchy thundery rain affects Scotland and Northern Ireland from dawn. A broad swathe of heavy rain across central and eastern Scotland during the day. Scattered thundery showers forming across England and Wales, but very hit and miss, with some parts over the Midlands and south escaping dry. Hazy sunshine and high cloud. Coastal fog in northeast, perhaps also locally in south. Varied winds, mostly light. Humid, 27 to 31C south and east. 17 to 22C northwest, cooler western Scotland.

Monday night
Rain continues to affect east, central and southern Scotland during the night, some prolonged heavy falls. Scattered zones of heavy rain and some thunderstorms over England and Wales. Drier for Northern Ireland, also the far west of Scotland where there will be brisk northerly winds. Mist forming after areas of rain. Some places staying dry. Fairly humid and mild, temperatures 12 to 17C for most, warmest in towns and cities in the south and east. Lows 9 to 13C in the rural north and west.

Tuesday
Extensively cloudy skies with rare sunshine. Areas of rain across Britain, but amounts will vary with some places more often dry. Thunderstorms increasingly forming over southern England, around the Home Counties and into East Anglia, perhaps also south Wales - some intense downpours in places. Persistent heavy rain toward northeast Scotland. Drier for western Scotland. Much of the day should be dry for Northern Ireland, breezy and quite cool. Highs 17C north to 25C south.

Wednesday
A front affects southern and central England and Wales with cloud and outbreaks of rain, before slowly retreating to the south. Some heavy and possibly thundery bursts locally in the southeast. A ridge of higher pressure builds into Ireland and Scotland bringing drier conditions here with some sunny spells, these edging southwards during the day. An Atlantic front approaches the far west of Scotland and Ireland later. Highs 20 to 23C in the south, 16 to 19C in the north.