What September feels like in Brussels
In Brussels, September brings early autumn. Afternoons are mild and comfortable for most people in light layers. There is little difference between day and night: nights are cool, and evenings feel much like the afternoon. The air is fairly humid, though at these temperatures it rarely feels oppressive.
Rain in Brussels in September
Expect a mix of dry and wet days, with rain about one day in 3. A rainy day brings about 5.3 mm (0.2 in) on average — steady rain rather than a passing shower. That is close to Brussels's typical rain per wet day for the whole year (about 5.4 mm). It is among the three driest months of the year.
Daylight and sunshine in September
In mid-September, sunrise is at about 7:16 am and sunset at about 8:00 pm (local time) — 12 h 44 min of daylight. Days are getting shorter: 1 h 54 min less daylight than in mid-August. Measured sunshine covers about 68% of the daylight — there are plenty of bright spells.
How September compares to the rest of the year
Ranked by average high, September comes out as the 4th warmest month in Brussels. Compared with August, afternoons are 2.9°C (5.2°F) cooler, with 16 mm less rain. October is cooler again. The next month's average high: 15.4°C (59.7°F).
Who September suits
- Sightseeing: a good fit — comfortable enough to explore on foot all day.
- Parks & outdoor: a good fit — pleasant for gardens, parks and riversides.
Tips for visiting Brussels in September
Rain Protection
A packable rain jacket saves the day on showery afternoons.
Sunglasses
Frequent sunshine — sunglasses and a light hat.
Quick questions
How warm is Brussels in September?
It feels mild: typical highs are 19.7°C (67.5°F), with lows near 12°C (53.6°F).
Does it rain a lot in Brussels in September?
Yes, fairly — rain falls about one day in 3 and totals about 53 mm, so an umbrella is worth carrying.
What should I wear in Brussels in September?
Pack rain protection and sunglasses. Evenings feel similar to the day, so the same clothes work from morning to night.
Is September or October better for visiting Brussels?
September scores better on our climate ranking (#1 of 12 vs #7), rated Great against Good. October is cooler and has more rainy days.