The weather will be hot and humid but will remain dry on Tuesday, says the Royal Meteorological Institute. However, thunderstorms may break out locally at the end of the day.
The temperature will rise to 22°C by the sea, 24°C in the high plateaus of the Ardennes and 26 to 28°C in most other regions.
The atmosphere will then become heavy and unstable as the day progresses and clouds gather. Thunderstorms are expected to advance over the west and then the centre of the country.
The Brussels Times