The UK is set for a changeable September, with Atlantic weather systems bringing periods of rain and wind while some southern areas experience warmer and brighter spells. After the country recorded its hottest summer since records began, forecasts from the Met Office indicate that temperatures through September are expected to remain close to seasonal averages.
Atlantic Influence Brings Mixed Conditions Across the UK
According to the Met Office, September is expected to continue the recent pattern of unsettled weather, with low-pressure systems bringing further rain, particularly across northern and western parts of the country. Southern and eastern areas are more likely to see drier periods at times.
Temperatures are forecast to stay around average or slightly above average for the time of year.Following a mild start to the week, highs are expected to reach 21C in London and 17C in Glasgow on Tuesday. Earlier in the week, temperatures could rise to 25C in London and 22C in Manchester and Cardiff, with parts of Scotland reaching 21C.
The BBC reported that warm and humid conditions were expected during the weekend, with some areas reaching the mid-20s Celsius. Rain is also forecast in parts of the country, with some heavier outbreaks possible alongside brisk south-westerly winds.
Southern England is expected to experience some of the warmest conditions, with parts of Wales, the Midlands and southern England potentially reaching 23-25C. Despite these temperatures, the BBC noted that the UK is not expected to meet heatwave criteria, which require three consecutive days above region-specific temperature thresholds.
The longer-range outlook remains uncertain, with weather models suggesting that the jet stream could continue to bring areas of low pressure towards the UK. This would maintain periods of rain and potentially blustery conditions, while later September may see more influence from high pressure and longer dry intervals.
September Records Show a Month of Extremes
September has historically produced a wide range of weather conditions across the UK, from late-summer heat to early signs of winter. According to the Met Office, the highest September temperature recorded in the UK was 35.6C at Bawtry in South Yorkshire on 2 September 1906.
That same heat event produced national records elsewhere. Scotland reached 32.2C at Gordon Castle in Moray on 1 September 1906, while Wales recorded 32.3C at Hawarden Bridge in Clwyd on the same day. Northern Ireland’s highest September temperature was recorded more recently, when Castlederg in County Tyrone reached 28C on 8 September 2023.
The month can also bring much colder conditions. The Met Office records show that the UK’s lowest September daily maximum temperature was 4.4C at Braemar in Aberdeenshire on 29 September 1915. Overnight temperatures have also fallen below freezing, with Dalwhinnie in Inverness-shire recording -6.7C on 26 September 1942.
Rain and wind extremes are another feature of September weather. West Stourmouth in Kent recorded 190.7mm of rainfall in one day on 20 September 1973, while the UK’s strongest September gust reached 112mph at Dounreay in Caithness on 28 September 1969. These records highlight September’s role as a month of transition, where warm spells can continue while Atlantic systems begin to bring more autumnal conditions across the UK.
