BBC monthly outlook
Summary
For most, staying largely warm and often dry
Saturday 21 July—Sunday 29 July
Very hot at times. Risk of thunderstorms later.
Monday will be hotter still across England, where light winds and long sunny periods will allow temperatures to climb into the low 30s Celsius across central and southern areas. Meanwhile, much of Scotland and Northern Ireland will continue to see a persistent lingering front bring cloudier weather, with some patchy rain continuing at times.On Tuesday, heat will persist across central and eastern England, while a fragmented band of cloud, rain and showers slides slowly south-east towards Wales and south-west England.
Wednesday will be dry and fine for much of the country, with the hot weather continuing for England. During the latter half of the week, it looks like more widespread heat and humidity will build across England and Wales, perhaps giving the hottest spell of the year so far, while passing fronts will give cloudier and cooler weather for Scotland and Northern Ireland at times.
There are growing hints of more widespread thunderstorm activity across the United Kingdom at the weekend, bringing a brief respite to the hot weather here.
Monday 30 July—Sunday 5 August
Generally dry and very warm
By the start of the week, it looks like there may be a temporary cool down, with a cooler westerly airflow pushing across most of the country, perhaps bringing temperatures back closer to average for most, although south-east England will likely still hang on to very warm weather. A gradual rise in temperatures is then expected through the week, with winds bringing increasingly hot air from the southwest and south at times.
During the latter half of the week, there is a chance of some further very hot days across England and Wales in particular. The hot weather may spark off one or two thunderstorms during the afternoons, although these are unlikely to bring any significant widespread rainfall. However, northern and western Britain is always likely to be cooler, with incursions of Atlantic fronts from the west or southwest breaking up any warmth and sunshine with cloud and rain at times, a familiar theme from previous weeks' weather.
Monday 6 August—Sunday 19 August
Remaining fine, warm and settled.
As we look towards the middle of August, the theme of very warm and dry conditions will persist for much of the country. The atmosphere is currently in a very lazy and slow-moving state, so there will be a notable lack of low pressure systems close to the UK, with higher-than-normal pressure more likely to dominate. As heat and humidity lingers from previous weeks over the UK,France, Germany, the Low Countries and Scandinavia, temperatures are likely to remain well above average, especially across the southern and eastern half of the country, which will be most prone to any hot flows of air moving off the near continent.
There will be a lot of dry weather too, with isolated heavy showers and thunderstorms during the afternoons the only real chance of rain for most. However, western parts of the UK may see frontal incursions from the west bringing bands of rain or showers for a few days. There is the potential for more widespread thunderstorms to push across England and Wales from France, should there be a hot plume of air moving up from this direction too. The main uncertainty is regarding how dominant low pressure will become; there is a small chance for cooler and wetter conditions to develop, should deeper areas of low pressure move across the UK from the west.
Next Update
Will the warm and summery weather last until the end of August?
https://www.bbc.co.uk/weather/outlook