Belgium will see some sunshine on Wednesday morning before clouds move in and rain spreads across the country later in the day, according to the Royal Meteorological Institute (RMI).
Sunny spells are expected across the south-east during the morning, while the west and north will already see more cloud.
Cloud will then increase from France during the afternoon, with the first rain expected in the second half of the day. An isolated thunderstorm is also possible.
Temperatures will reach around 18°C at the coast, 21°C to 22°C in central Belgium and up to 23°C or locally 24°C in the east.
Rain will spread to all parts of Belgium during the evening and overnight. It could become heavy in the south-east, where thunderstorms are also possible.
Conditions will briefly become drier in the west later in the night, but showers from the North Sea are expected to reach the coast before morning.
Temperatures overnight will fall to around 8°C in the High Ardennes, 12°C in central and western Belgium and 14°C at the coast.
Winds will also strengthen overnight. Gusts could reach around 60 km/h inland and between 70 and 80 km/h along the coast, according to the RMI.
On Thursday morning, the rain will gradually leave the east, while showers from the North Sea spread across western and central Belgium. They will move east during the afternoon, bringing changeable and showery weather across the country.
