The UK weather forecast September points to a warm weekend, but no area is expected to reach heatwave criteria. Temperatures are set to climb across the UK, with cooler conditions due back by midweek.
South-east England and Wales
On Saturday, outbreaks of rain will spread southwards, with some of the rain potentially heavy and a chance of thunder and lightning. Southern parts of England should stay largely dry, with sunny intervals and temperatures that could climb into the mid-20s Celsius.
Typical mid-September temperatures range from 14C in northern Scotland to 19C in south-east England. The forecast is above that range in several places, but it still falls short of the three-day threshold that would be needed for a heatwave.
England and Wales on Monday
Rain may linger for a while in southern England on Sunday before clearing to leave a dry afternoon for much of the UK. Much of the UK is expected to have sunny spells and light winds, with parts of Wales, the Midlands and southern England reaching 23-25C.
Monday could be even warmer, with highs of 22-26C across much of England and Wales and temperatures of 20C likely in parts of Scotland and Northern Ireland. The warmth will persist into Monday in many areas, but the weather will remain below the criteria for a heatwave.
Later in September
Computer weather models paint a very mixed picture for the second half of September. They currently suggest unsettled weather will continue over the next week or so, as the jet stream brings areas of low pressure across the UK and spells of rain with potentially blustery winds.
Later in the month, areas of high pressure may have more influence on the weather, bringing longer dry interludes and the chance of above-average daytime temperatures. For now, there is nothing to indicate that a heatwave is on the cards, so the practical expectation is a warm spell, rain in places and a cooler turn by midweek.
