Snow is falling across parts of the UK as very cold air sweeps in from Russia.
Yellow and amber weather warnings for snow are in place for Monday in much of southern and eastern England - with warnings extending into the Midlands, Scotland and Wales on Tuesday morning.
Many areas have been hit by freezing temperatures, with a wind chill making it feel like -15C in some places.
Todays Farming Weather forecast with @FarmersGuardian for the Week & Weekend Ahead has all the latest on the cold and snow risk. Watch now at t.co/npguIGzz1f #farming #weather #uksnow pic.twitter.com/VqeIe3TqE7— Weatherweb (@wxweb)
By Wednesday night, more than 20cm (8ins) of snow could have accumulated in some parts of eastern England and Northern Ireland, forecasters have warned.
Scotland is expected to have between 5cm (2ins) 10and 10cm (4ins) of snow on Wednesday.
Specialist forecaster Simon Keeling told Farmers Guardian: "Extreme cold is going to be hitting the UK, Ireland and much of central and Northern Europe this week.
"The cold extends into the west of Russia with temperatures as much as 10C below the average for the time of year.
"Severe overnight frosts are anticipated with temperatures in the UK as low as -10C overnight and down to -20C in parts of Eastern Europe.
"Daytime temperatures in the UK and Ireland will not be rising above freezing for most on Wednesday and Thursday. Add to this the effect of the strong east wind and it really will be feeling bitterly cold.
"Snow will be accompanying the cold across much of Northern Europe. In the UK it will be eastern areas that see most of the snow.
"The good news for those wishing to spread slurry is that the ground is going to be harder than in recent weeks and the dry air above (despite the snow showers) should aide this.
"However, by the end of the week more persistent snow may be extending through Ireland, Wales, central and southern England, ahead of some milder air using into the far south.
"Current thoughts are that the battle between cold air to the north and milder air to the south continues into next week with wetter conditions in the south of the UK and Ireland, rather murky here with slightly milder temperatures.
"Scotland remains cold in an easterly wind although not as cold as this week."