Tuesday will begin with a risk of fog across the western half of Belgium before turning widely sunny, but a sharp change is expected later this week as rain and autumnal conditions return, according to the Royal Meteorological Institute (RMI).
By Tuesday afternoon, skies will be fairly sunny, with temperatures ranging from 17°C on the coast to 23°C elsewhere.
Tuesday night into Wednesday will be partly cloudy, with lows between 7°C and 13°C.
Wednesday will start with long sunny spells, but clouds will build during the day as a band of rain moves in from France towards the evening.
Temperatures will rise further, reaching up to 24°C in some areas.
The weather will change sharply on Thursday, with unsettled conditions, frequent showers and wind gusts of 50 to 60 km/h.
Temperatures will also fall significantly, with highs of just 11°C to 15°C.
Further bands of rain are expected on Friday and Saturday, with maximum temperatures of around 10°C in the High Ardennes and 15°C in central Belgium.
