Freezing air from Russia is to grip the UK in what is set to be the coldest late February in five years.
The cold blast – dubbed the beast from the east – will see temperatures plunge below zero from Sunday night, with some areas seeing lows of minus 8C (17.6F), while snow is set to fall in London.
A forecaster joked that spring had been “postponed” due to the chill arriving from the east just before March 1 – the first day of the meteorological spring.
Met Office meteorologist Martin Bowles said the mercury will drop to as low as minus 5C (23F) in London on Sunday night, while snow is likely in the capital from late on Monday and into Tuesday.
Temperatures of minus 8C are expected widely across the rest of the country.
Mr Bowles said: “Somewhere like the Scottish mountains might go lower than that, but that’s actually quite normal in the Scottish mountains, whereas it’s definitely not normal to have minus 5C in London at the end of February.
“We haven’t had temperatures that low in late February since 2013. It’s not unheard of. There are records that are lower than that.”
He added: “But it is quite unusual, particularly as it’s quite late in the season.
“We refer to March 1 as being the first day of spring and of course March 1 will be right in the middle of this cold spell, so spring will be postponed for a couple of weeks, shall we say.”
During the day on Monday, temperatures of 1C (33.8F) and 2C (35.6F) are expected across much of the country, while Northern Ireland will escape the worst of the cold due to its western position.
Snow is expected mostly in eastern areas, with snow set to accumulate in some parts.