Monday will begin with patches of mist and fog, followed by a partly cloudy and dry day, according to the Royal Meteorological Institute.
In the south-eastern slopes of the Ardennes, low cloud and fog are expected to linger for longer.
Temperatures will range from 4°C in the eastern highlands to 10°C in Flanders and central regions. Winds will be light to moderate, blowing from the south to south-east.
Cloud cover will thicken by the evening, with rain moving in from France and the western parts of the country.
Overnight, temperatures are expected to fall between -1°C and 5°C. Winds will strengthen slightly, remaining moderate and coming from the south-east.
