Met Office forecasters have predicted that there is a 70 percent chance of severe conditions which could impact the most vulnerable, including the elderly. Regions that will be most impacted by the severely cold conditions are in the southwest and southeast of England.
The east of England, the east Midlands and the west Midlands will also be hit by a wall of freezing weather.
Overnight, temperatures have dropped so far to -6.8C (19.7F) in north Yorkshire.
And temperatures are expected to fall again to -6C (21.2F) or -7C (19.4F) overnight on Monday.
Northern Ireland recorded its coldest night of the winter which was -6.2C (20.8F).
Public Health England (PHE) has even published a warning for vulnerable people.
They wanted older people and those with heart and lung problems that they are most at risk of getting sick in cold weather.
PHE are telling people to be aware of those who may need help staying warm which includes wearing multiple thin layers and making sure they have everything they need.
Reportedly, heating homes to at least 18C (64.4F) is important.
Air pressure reached 1050.5 millibars in Mumbles Head in Wales on Sunday.
This is the highest level since January 16 1957, when it hit 1050.9 millibars in Benbecula in the Outer Hebrides.
High air pressure has been known to impact television and radio signals.
It’s possible that those with Freeview could possibly miss their favourite programmes because of the high pressure.
The high pressure can bend or reflect TV and radio waves which interferes with the signals.
A spokesman for Freeview said: “Your aerial is not able to pick up the same quality of signal that it normally would.
“As a result, some viewers may experience a pixelated picture, or in some cases a temporary loss of certain channels.”