Friday
A frontal system moves slowly across northern Britain, bringing grey skies, rain or drizzle for many hours. Some steadier rain will set in for north-west England and north Wales by the middle of the day into the afternoon. Early rain in Scotland will fade to leave drizzly showers. Southern England & Wales stays largely dry, but clouding over. A risk of isolated thunderstorms in the south-east by evening. Warm and humid south, 25 to 28C. Nearer 17 to 19C north, cooler in rain.

Friday night
Weakening fronts continue to drift southwards. Widely murky and damp, with patchy rain or drizzle for Wales, the south-west and the Midlands. Little if any rain reaching central & south-eastern England, apart from localised remnants of any thunderstorms from Friday evening. Generally cloudy but dry for northern Britain, with local drizzle. Light winds, locally gusty near coasts in west. Staying muggy in the south, 14 to 17C; fresher in the north, lows 9 to 12C.

Saturday
A little rain or drizzle in the south at first, but fading to leave most places dry all day. Western areas may hold onto mostly cloudy skies, whilst eastern districts should see sunshine breaking through. A warm front approaches the far north-west, bringing lowering cloud and drizzle to Northern Ireland and western Scotland later. A west to northwesterly breeze, quite blustery for western England & Wales. Highs 18 to 22C north & west, up to 23 to 26C south-east.

Sunday
Fronts moving close to north-western Britain & Ireland bring cloudy skies and some rain or drizzle, chiefly affecting western Scotland, accompanied by a fresh southwesterly breeze. For much of the country, it will be a dry and warm day with good amounts of sunshine. A light west to northwesterly breeze for England & Wales. Temperatures ranging from 18 to 21C in the north & west, up to 26 to 29C in central-southern England.