The Met Office has issued a cold weather alert at level 3 (severe weather action) - the levels go from 1 (Winter preparedness and action) to 4 (National Emergency).
The alert is in place until 3pm on Friday (January 6).
The Met Office says a further period of cold conditions is due to a brief northerly air flow developing, before pressure builds across England overnight, leading to a widespread frost.
“Thursday then remains cold, with further frost likely overnight. Less cold air will then move in from the west through Friday. Coastal fringes are likely to remain marginally less cold than further inland.”
Temperatures inland could reach as low as -4degC tomorrow morning, with a daytime high of just 3degC.
Coastal areas in Sussex are likely to be just a degree of two higher.
During Friday the wind direction is set to move from a northerly direction to a more southerly direction, bringing warmer weather.