The Royal Meteorological Institute (IRM) issued a yellow warning on Saturday for slippery conditions in the provinces of Liège and Luxembourg, following an earlier alert the night before.
This weekend, forecasters predict wintry showers in the higher regions of the Ardennes, making roads slippery.
During the day, the snow-rain limit will be around 500 metres, dropping to 300 or 400 metres at night with possible snow accumulation of 1 to 5 cm.
After a break on Sunday evening, the east of Belgium will see more snow or rain on Monday, with accumulation exceeding 5 cm in less than 24 hours.
The warning for slippery conditions started on Saturday at 12:00 and will run until Monday at 22:00 for the Liège province, pausing from 11:00 Sunday until 04:00 Monday.
For Luxembourg province, the warning will only apply from 04:00 to 22:00 on Monday.
Additional fog could potentially reduce visibility to below 200 metres in the Ardennes highlands. The fog-related yellow alert is in effect from 19:00 Saturday to 13:00 Sunday.