After an unseasonably warm start to November, temperatures are expected to fall sharply from Sunday onwards.
Weather maps show parts of the country being hit by snow and freezing conditions.
The sharp fall is due to ‘Arctic air’ coming in off a strong northerly wind, and will last until the end of the month.
Temperatures are forecast to drop to around 5c to 9c by day, 4c to 0c by night with widespread frosts for most areas.
Wintry showers are expected to start falling around November 21-30, snow is most likely to occur on the higher hills of northern England and Scotland, with the possibility of some wet snow down to lower levels.