The Met Office has issued a yellow weather warning for snow across the south east on Sunday.
Forecasters have said high pressure over Scandinavia will feed a very cold easterly airstream across the country.
As the air crosses the North Sea it could leave two to five centimetres of snow in places.
In Portsmouth we could see light snow between 3am and midday as temperatures fall below freezing.
There is a cloudy outlook for the rest of the day, with warmer temperatures on Monday to help clear any snow which appears.
Heavy snow showers earlier this month caused major travel disruption in Portsmouth.
The weather warning is in place between 12.05am and 11.55pm on Sunday.