After the early part of this week (showery, possibility of thunderstorms), it looks like there's finally an improvement although as OYBBK says, could be some rather high temperatures on the way for some.
Long-range forecast from the metoffice.....
17th-26th August
High pressure to the east is most likely to dominate, certainly at first, but with low pressure close by to the west or southwest, and probably making some inroads across the country although the extent and timing is uncertain. A spell of sunny, very warm to hot weather is likely to develop. Many areas, especially in the south and southeast, could expect to see temperatures above 30 Celsius. There is low confidence in the extent and duration of high temperatures, , with exact wind direction and speed key. There is a risk of rain and thunderstorms in the west or southwest at first, which could extend east to all areas through the period, with chance of cooler conditions following. Equally, this could remain to the west, with warm/hot conditions persisting.
27th August-10th September
A changeable pattern is likely towards the end of August and into early September. This perhaps with the wettest conditions over the north and northwest. There is a probability for thunderstorms developing within warm interludes, especially in the south, but perhaps spreading across the UK at times, which could lead to large local variations in precipitation totals through the period. This might contribute to an unequal distribution of precipitation across the country. Temperatures are likely to trend down to near or slightly above average, although warm spells remain a possibility.