Brussels Weather in September
Belgium · Oceanic climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Brussels sees average temperatures ranging from a low of 12.4°C (54.3°F) to a high of 20.8°C (69.4°F), with a mean of 16.4°C (61.5°F). Compared to the annual average of 11.5°C (52.7°F), this month is 4.9°C warmer than the yearly norm. Precipitation averages 75.2mm, making it approximately 2.0mm wetter than the monthly average of 73.0mm. The city receives an average of 9.2 hours of sunshine per day during September, with relative humidity averaging 77.2%. Wind speeds reach an average maximum of 18.4 km/h. For travelers, this month offers a temperature experience in Brussels, with wetter-than-average conditions compared to the rest of the year.
Brussels has an oceanic climate similar to London but with slightly warmer summers. I've studied the data and found that the city receives moderate rainfall year-round, with no distinct dry season. The best time for visiting is May to September, when temperatures are most pleasant and the city's outdoor cafés and markets are at their best.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 19.2°C (66.6°F) | 16.4°C (61.5°F) | 12.6°C (54.7°F) |
| Rainfall | 57.5mm | 75.2mm | 92.5mm |
| Sunshine | 10.9 hrs | 9.2 hrs | 6.2 hrs |
| Humidity | 72.6% | 77.2% | 82.7% |
| Wind | 18.7 km/h | 18.4 km/h | 22.6 km/h |
| Rainy Days | 18.4 | 16.0 | 19.6 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Brussels in September, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Brussels in September?
The average temperature in Brussels during September ranges from 12.4°C (54.3°F) to 20.8°C (69.4°F), with a mean of 16.4°C (61.5°F).
How much does it rain in Brussels in September?
Brussels receives an average of 75.2mm of precipitation in September, spread across approximately 16.0 rainy days.
What should I pack for Brussels in September?
Based on September weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is September a good time to visit Brussels?
September is a good time to visit Brussels, with comfortable temperatures and manageable rainfall.
Other Months for Brussels
Cities with Similar September Climate (Oceanic)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 50.85°, 4.35°. Timezone: Europe/Brussels. Last updated: 2026-07-30.