The mercury is likely to plunge to between -2 and -4 degrees in low-lying areas, and could drop to -10 in the Scottish Highlands.
Meanwhile, in the Icelandic capital Reykjavik, it will be a relatively balmy two degrees above freezing, while in the Russian city of St Petersburg the mercury is not predicted to dip below freezing point.
Snow has already hit north-east England and Scotland, and the Met Office has predicted further snowy showers and ice later in the week.
Thursday is expected to be the coldest night, and the UK's lowest temperature this autumn has already been recorded at Topcliffe in North Yorkshire, where it dropped to -6.3 degrees.
Around 10cm of snow is predicted for the North York Moors on Thursday, with a lighter sprinkling at lower levels.
The cold snap is due to brisk air from the north, although daytime temperatures in England will likely remain above freezing.