Saturday
High pressure builds to the east on Saturday. Varying amounts of cloud around through the day. Murky with some drizzly outbreaks of rain for western parts of Scotland and Ireland. Brighter to the east. Showers spreading across Ireland, Scotland and the north of England through the afternoon turning to more prolonged and heavier outbreaks of rain for Ireland later. Staying mostly dry for England and Wales. Breezy in the west. High temperatures at 14 to 18C for Scotland and the island of Ireland, 20 to 23C for England and Wales though 25 or 26C is possible in the southeast.

Saturday night
Rain spreading from Ireland across Scotland and into northwestern parts of England and Wales through the night from Saturday into Sunday. A cloudy night across the country but staying dry for much of England and eastern Wales. A muggy night with overnight lows from 10 to 17C for most.
 

Sunday
An area of low pressure to the west of Ireland and sends fronts across the British Isles. A wet start to the day for Scotland and eastern parts of Ireland, dry but overcast for much of England and Wales. Rain will spread into England and Wales becoming increasingly showery though there will be some heavy bursts for Cumbria and the southwest. Showers behind this to the west for Ireland and Scotland. The far southeast of England should stay dry and highs will reach up to 27C here. More widely at 19 to 24C across much of England, 15 to 20C for the island of Ireland, Scotland, Wales and southwest England.

Monday
A fresher southwest to westerly flow is likely on Monday as a weakening cold front passes eastwards. A mix of sunshine and locally heavy showers. Rain may become more frequent in western Scotland as well as southwestern parts of England, Ireland and Wales. Breezy, or windy around coasts and hills in the west & north. The best of the brightness in the northeast. High temperatures widely at 14 to 17C. Cooler in northwest Scotland at just 12C, warmer in southeast England at 19 or 20C.