London is set for a bitter shock this week as a plunge of Arctic air descends upon the UK, threatening the capital with its first wintry precipitation of the season. The BBC Weather forecast indicates that icy sleet could hit London in the early hours of Thursday, November 20, marking a stark contrast to the recent spell of mild weather.
A Chilly Turn for the Capital
The Met Office has confirmed that snow and ice are possible following a period of above-average temperatures. The frosty conditions are expected to take hold after the UK recorded its coldest night since March during the recent Storm Claudia. Thursday will see temperatures struggle to reach a high of 6°C, with the sleet shower predicted for around 1pm, accompanied by sunny intervals and further intermittent rain.
Dan Holley, Deputy Chief Meteorologist at the Met Office, emphasised the severity of the change. He stated, "There will be widespread frosts across the UK, with temperatures dipping as low as minus 7°C in places, and daytime temperatures staying in single figures across the country. Couple this with a brisk northerly wind, and there will be a marked wind chill." He added that this shift will be particularly noticeable after the prolonged spell of unseasonable warmth.
London's 7-Day Weather Outlook
Here is the full BBC Weather forecast for London, showing a gradual cooling before a slight rebound:
- Monday, November 17: 9°C/13°C, sunny intervals and light winds
- Tuesday, November 18: 7°C/3°C, sunny intervals and light winds
- Wednesday, November 19: 7°C/2°C, light rain and light winds
- Thursday, November 20: 6°C/2°C, sleet showers and a gentle breeze
- Friday, November 21: 7°C/3°C, light rain and light wind
- Saturday, November 22: 7°C/5°C, light rain and light wind
- Sunday, November 23: 10°C/7°C, light rain and light wind
Sunday is expected to be the warmest day of the week, offering some respite from the cold snap.
Why is Snow So Hard to Forecast in London?
Predicting snow in the capital is a notorious challenge for meteorologists. The likelihood of snow falling in London is inherently lower than in more northern parts of the UK, but the variability is also incredibly localised. It is common for one street to see rain while another, just minutes away, experiences a dusting of snow.
Weather expert Ian Currie explained this oddity to MyLondon, noting that temperature differences at varying heights are the key factor. "Snow is very dependant on the height of where you are. For every 50 feet, 15 metres or so, you get higher up there is an increased likelihood of an extra day of snow," he said.
He provided a clear example: "So if you take parts of South Croydon for example, Sanderstead and Selsdon, you are likely to get 10 more days of snow a year there than parts in the north of Croydon. It can change that much in a small distance. Again out by Biggin Hill there is much more chance of getting snow than Streatham or Tooting." This sensitivity means that a forecast can be thrown off by a tiny shift in a weather system's path or a minor temperature fluctuation, making the difference between a rainy and a snowy day.
