Sunday
A weak front is going to be bringing some cloud through much of central, eastern and southern England on Sunday morning. Mostly dry, but I'm not sure can't be ruled out. Brighter and fresher across much of northern England, Scotland, Wales, and Southwest England, as well as island with lots of dry weather and a moderate south-west wind. A few showers affecting western parts of Ireland and the far north of Scotland. The afternoon stays with broken clouds across eastern England, but other areas dry with sunny spells, although again a few showers in western Ireland and perhaps southern Scotland. Windier in western Scotland with some rain in the Hebrides as the winds reach gale force. Highs at 28C in southeast England, 18C in Ireland and western Scotland.

Sunday Night
A dry night for most with clear spells and well broken cloud. There could be more clouds in south-west England with some fog around coasts and its drifting into southern coasts of South Wales and southern Ireland. Clouds in a few spots of showery rain in central and western Scotland. Lows at 9 to 14C.
 

Monday
Higher pressure will be building on Monday. This brings plenty of dry weather with some good spells of sunshine. There may be some plan drifting through England in the morning and low cloud affecting south-west England and southern Ireland. A few shots for Northern Ireland and Southwest Scotland, but for most the day is going to be dry and bright with some further sunshine through the afternoon. Highs at 15C in northern Scotland, 26C in southern England.

Tuesday
A small area of low pressure drifting west to east through the British Isles, during Tuesday, brings the potential for some showery, and quite heavy, and potentially thundery rain. At the moment, most of the rain looks to be through northern England, southern Scotland, Ireland and parts of Wales, although almost anywhere, is it threat from seeing the thundery, showery rain. However note confidence in the forecast for Tuesday is low. Temperatures reaching 28C in the southeast of England, 15C in Scotland.