Saturday 24 Jul - Monday 2 Aug
High pressure begins to lessen it's grip by Saturday, as it drifts northwards. As it does so, more unsettled weather moves in for the weekend, starting in the south as heavy, possibly thundery, rain Saturday. Remaining very warm with plenty of sunshine in the northern half of the UK, and possibly locally hot, especially in the northwest. Cooler for some northern areas and windward coasts. Some low cloud, mist and sea fog can be expected for some of these areas, as well as parts of the southwest into Sunday. For the rest of the period, spells of rain or showers are likely for many areas, with some heavy rain or thunderstorms possible at times. Temperatures just above average for most, to modestly above average in the north. Winds remain light.
Tuesday 3 Aug - Tuesday 17 Aug
By early August, warmer and drier-than-average conditions look likely to return for much of the UK, although there is an increased risk of thunderstorms, especially in the southeast. By mid-August confidence becomes rather low, but with changeable conditions most likely. Above-average temperatures continue to be signalled for much of the period, perhaps becoming very warm or hot at times in the south.
https://www.metoffice.gov.uk/