Brussels Weather in September
Brussels in September sees pleasant daytime temperatures of 21°C (70°F) and nighttime lows of 11°C (52°F). Rainfall is fairly high this month at around 61 mm (2.4 in), so pack a rain jacket to stay dry.
Rainfall in Brussels in September
Historically, approximately 16 days this month are expected to have rain, averaging 61 mm (2.4 in). With rain spread across many days but low totals, showers are typically short and light rather than heavy.
Temperature in Brussels in September
Weather in Brussels is at its perfect in September. Highs reach 21°C (70°F), while nights settle around 11°C (52°F). Even when the weather is stable, mornings and evenings can still feel distinctly cool. Nights drop to around 11°C (52°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.
Sunshine in Brussels in September
The month brings about 142 hours of sunlight, offering a comfortable mix of sun and overcast.
Wind Speed in Brussels in September
September has wind speeds averaging 3 m/s (6 knots). You can expect comfortable light winds that steadily move flags and feel mild throughout the day. Since this is an average, daily conditions vary from gentle winds to more active breezes.So this is a great month to visit if you prefer dry days with pleasant temperatures.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Belgium, check out our Brussels's climate page.
Brussels Temperature in September
Min Temperature
11°C (52°F)
Max Temperature
21°C (70°F)
Chance of Rain
52%
Precipitation
61 mm (2.4 in)
Rainy days
16 days
Humidity
77%
Windspeed
3 m/s (6 knots)
Sunshine
142 hours
Percentage Sunshine
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Brussels typically stay consistent throughout September, with daily highs averaging around 21°C (70°F). Nights are cool, with lows typically ranging from 10°C (50°F) to 13°C (55°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Brussels in September
Browse day-by-day weather records for Brussels spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Brussels historical weather extremes in September
According to our 49 years of weather records for Brussels, the following extremes were recorded between 1976 and 2025.
- The warmest day in September was on September 15, 2020, with a maximum of 34°C (93°F).
- The coldest September day was on September 22, 1996, with a maximum of 10°C (50°F).
- The coldest night in September in Brussels was on September 19, 1977, with a minimum of 2°C (36°F).
Best Places in Belgium in September
Find out more about the weather in Belgium and which places have the best travel conditions in this month. See all of Belgium in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Brussels in September
Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Rain gear is recommended, you can expect wet weather on multiple days. Bring sunglasses since you'll have some sunny periods throughout the monthWhat To Do in Brussels in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Belgium, check out our Brussels's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed
See the full Brussels climate overview or explore weather in Belgium.
