As the UK's November cold spell ends, how unusual was it?

We are coming out of a major November cold spell, where some parts of the UK had four or five successive days with lying snow. There was a considerable thaw for many on the Tuesday due to high dew points and relative humidity, but in some areas the snow was deep enough for some of it to survive. Snow is less likely to fall and to stick around at above-freezing temperatures if the air is humid. For many there was somewhat less of a thaw on Wednesday through Friday because a dry Arctic air mass took over and the relative humidity was lower.

A common observation online has been that this spell was very early. The reality around this is complicated, because even in today's warming climate it is not that unusual to get lying snow to low levels sometime around 20 November, but it is rare for it to stick around as widely as we saw last week, and it is rare for temperatures to drop as low as they have done recently. With the warming climate, such snow events are tending to become more localised and more restricted to high ground with time, but as last week showed, widespread snow cover to low levels is still possible around or shortly before 20 November.

Looking back in history

Since the turn of the 21st century, there have been various snow events at a similar time of the year, including 18 November 2004, 22/23 November 2008 and 21 November 2015, but on each of those occasions lasting accumulations of snow were confined to a much smaller area of the UK. Two earlier ones also spring to mind - 8/9 November 2001 in parts of the north and east, and 9 November 2016 in the Vale of York - but again on those occasions lying snow was not as widespread, and on neither occasion did it last long on low ground. We have also had a couple of late October snow events that produced a snow cover to low levels in parts of England and Wales, in 2008 and 2012, but again accumulations were quite localised in both cases. The most famous recent example of November snow, in 2010, was more severe and widespread than the one that we've just had, but that spell didn't get going until 25 November. Other November snow events in 2017, 2021 and 2023 also didn't set in until near the end of November.

In the 1980s and 1990s, when we got a widespread snow cover in November, it generally set in on or after the 20th (this happened in 1980, 1985, 1988 and 1993), although there were fairly widespread snow events on 17 November 1995 and 19 November 1996. The November 1996 cold spell in particular was quite similar to the one that we've just had.

Widespread lying snow between 15 and 20 November was relatively common during the 1960s and the early 1970s (1962, 1965, 1969, 1971 and 1973) and there were more localised examples in 1977 and 1979. Further back, it was also quite common in the 1910s and 1920s, but it was rare between the 1930s and 1950s.

Overall, some individual locations have had their earliest lying snow event in the season since at least the 1960s or early 1970s. For example, parts of Devon had their earliest lying snow since 17 November 1972. However, when taking the UK as a whole it is not so easy to say that "this was the earliest widespread snow event since X" because it depends on what measures one is using. It is safe to say, though, that this has easily been the most notable November cold spell since the very famous one at the back end of November 2010 which led into the record-breaking cold December of 2010.

Looking further ahead

The recent cold spell was in many ways a dramatic contrast to the first half of November 2024, which for most of the UK was dominated by anticyclonic gloom, dull and very dry with temperatures often a bit below average by day, but very mild nights under the cloud cover.

The upcoming weather will provide a further contrasting episode: it looks probable that we will now see mild and changeable south-westerlies for most of the rest of November. There may be a brief colder, dry, sunny spell next Wednesday/Thursday, particularly in the north. Otherwise, the wet and windy weather of this weekend will give way to sunshine and showers on Monday/Tuesday, and then mild and cloudy south-westerlies are expected to set in from next Friday onwards, with potential for some heavy persistent rain in the north-west, but drier weather towards the south-east.

Into early December there is a lot more uncertainty, and some of the medium-range forecast model runs are pointing towards potential for cold Arctic northerlies to return during the first week of the month. This is by no means a certainty, but it is worth watching.