Will the fine, very warm weather last throughout the weekend? Not quite, but it will still be warm in the south on Saturday.
Max. UK temps : Thursday 19th April just over 29C. Hottest April day in 70 years, very close to the UK April record, Forecast - Friday 20th 26C, Sat 25C Sunday 21C
Thursday will see the highest temperatures this week, with light winds and over 28C in London. As high pressure stays over the UK on Friday the fine weather and heat remains 25/26C is still possible.
By the weekend, London could still see mid 20's with much of inland Wales and England up into the low 20'sC (if you divided the UK north-south). For northern Britain and Northern Ireland still some spots reaching 18C and feeling warm enough but more of a range in the teens.
There is also an increased risk of showers, so after the mainly fine weather of Thursday and Friday, hefty, even thundery downpours will affect a few places. Sunday looks more unsettled with Atlantic frontal bands moving across the UK west to east. So more chance of cloudy skies and showery rain.
If you are thinking of heading to the beach, let's consider the wind direction. Inland it can be warm and cosy, by the sea a bit more bracing.
Friday evening, still very light but there could be a sea breeze for the south and east coast of England, overall light winds.
Saturday - there will be a more noticeable southerly wind. Light for SW England and Welsh coasts but brisk along the English Channel and backed enough to the SE to perhaps clip North Sea coasts.
London Marathon- 20C, warm but not as warm as Thursday. Moderate west wind. Dry with lengthy sunny spells
UV levels are up, (tree) pollen levels and moderate air pollution in the south is forecast.
And yes, next week does turn colder. Back to frost in the Highlands and wintry showers over the Scottish mountains and only 13 or 14C in London.