Brace yourselves for a drop in temperature in the next 24 to 48 hours.
Colder Siberian air will seep in on easterly winds.
After a cold, crisp weekend, expect it to feel even colder into a new week - with a marked windchill.
As showers get going with the colder air there'll be a wintry flavour with a little sleet and snow in places over the high ground of the Pennines, and possibly as far south as the Downs and the Moors - especially through Tuesday night into Wednesday morning.
It'll turn icy - particularly through the nights and early mornings - with slippery surfaces in places.
Temperatures fell as low as -5C in Scotland over the weekend and it's expected there'll be similar temperatures Wednesday night into Thursday morning.
It'll be frosty for rural zones in the next few nights but a brisk breeze will prevent it getting colder and keep notable mist and fog at bay.
Come later in the week, temperatures will tend to recover and it won't feel as cold by the weekend.
Cold snaps in November are not unheard of but usually brought about by a northerly wind rather than an easterly airflow.
The last time colder November air arrived in this set up was November 2010 - ahead of one of the coldest, snowiest Decembers on record.