Port city, Rupel and the Campine
The province of Antwerp runs from the Scheldt port in the west to the Kempen in the east and is completely flat. Antwerp stands at 10 metres on a broad tidal river, Mechelen on the Dijle likewise at 10, and even Turnhout in the north-east reaches only 30. Weather here is made not by terrain but by the movement of air masses, by the river, and by sandy soils that give up and take on heat quickly.
The normals show it. Antwerp averages a January night-time low of 1.6 degrees, the Kempen town of Mol 1.0, and in July the metropolis reaches 23.2. Mechelen, one of the warmest places in the province, averages 24.0 in July. The gap between town and heath is small, yet in winter it is often the difference between rain and snow.
City, port and heat island
A port city like Antwerp gathers a lot together. Port industry, dense traffic and acres of concrete form a heat island that warms summer nights and makes winter frost slightly rarer. The river gives off moisture, fog forms most readily on autumn mornings along the Scheldt, and the tidal range of the Scheldt is felt far inland. With 823 millimetres a year on 149 days, Antwerp sits at the Belgian average.
Residents of Brasschaat, Schoten or Kapellen experience a similar climate with more greenery. The northern suburbs border woods and heath, which cool faster at night. The differences are tenths of a degree, but on clear winter nights you notice them: hoar frost on car windscreens while the old town still enjoys plus degrees.
The Kempen: sand, heath and frost
East of Antwerp the Kempen begins, a landscape of pine woods, moorland pools and sandy soil. In Turnhout (January low 1.1 degrees), Geel and Balen the air cools harder than in the city on clear nights, because porous soil stores little warmth. Early frost in October and late frost in May are more common than at the coast, as local farmers and gardeners know.
Heat, by contrast, reaches extremes quickly on sandy ground. In high summer the heathland dries out fast, and wildfire risk becomes a topic in the pine forests near Kalmthout. Kalmthout and Ravels on the Dutch border offer quiet and open space but little shade on hot days. Walkers there carry plenty of water, and cyclists prize the cool early hours.
Tomorrowland and open-air festivals
In summer the province turns to outdoor events, above all the electronic music festival Tomorrowland in Boom, which draws huge crowds. Boom lies at 10 metres on the Rupel, the site is open, and heat, thunder or sudden downpours decide mood and safety. The Rupel itself is a tidal river whose level climbs noticeably after heavy rain.
Summer evenings matter for thunderstorm risk. Instability builds in the south and west and often moves over Mechelen towards Antwerp. Anyone partying outdoors in the evening opens the radar map and watches for red cells. The next 14 days in Antwerp give a direction that you check against short-range warnings.
Pollen and neighbours
The open fields and pine woods of the province are not easy terrain for allergy sufferers. Pine pollen falls as yellow dust on cars in spring, grass pollen follows in summer. Our guide Pollen in Flanders and Wallonia sums up the season. In the north the wind often arrives off the sea, in the east off the heaths, and that shapes what is in the air.
Limburg adjoins to the east, East Flanders to the south-west and Flemish Brabant to the south. Crossing the province you hardly change clothes, yet the wind regime shifts from maritime in the west to continental in the Kempen. A closing look at autumn: when a low approaches over the Scheldt, the water level in the port often climbs by several decimetres, and the storm-surge barrier becomes a topic of conversation. Riverside walkers do well to check the tide times first.
Sources and further reading
IRM-KMI: Royal Meteorological Institute of Belgium
Waterinfo: river levels and flood situation in Flanders