Weather in Brussels in September
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Book now, pay at pickup — compare Hertz, Avis, Budget, Sixt and 800+ rental companies for September in Brussels.
Compare car hire prices → Affiliate link — we earn a commission at no extra cost to youBrussels in September is pleasantly mild — daytime temperatures average 21.1°C, dropping to 12.5°C at night. The month is moderately rainy (10 rainy days), with roughly 9.4 hours of sunshine a day. It is one of the best months of the year to visit. For the complete picture, see the best time to visit Brussels — every month compared. Once you know when to go, find your Brussels packing list at 247PackingList.
Get ready for Brussels in September
Search flights to Brussels
Compare 100+ airlines for September — one search, best price.
Search Flights →Travel clothing layers
Pack layers — temperatures can vary significantly between day and night.
Check Price →What to pack for Brussels in September
- Light layers
- Sunscreen
- T-shirts and light trousers or shorts
- Light waterproof layer
Compare all months in Brussels
| Month | High | Rain | Rating |
|---|---|---|---|
| January | 6.7°C | 70.7mm | 10/10 |
| February | 9.0°C | 71.1mm | 10/10 |
| March | 11.0°C | 64.4mm | 10/10 |
| April | 13.7°C | 40.5mm | 10/10 |
| May | 17.9°C | 52.6mm | 10/10 |
| June | 22.7°C | 74.5mm | 10/10 |
| July | 22.3°C | 93.4mm | 10/10 |
| August | 23.5°C | 58.4mm | 10/10 |
| September | 21.1°C | 68.9mm | 10/10 |
| October | 16.0°C | 97.8mm | 10/10 |
| November | 10.6°C | 66.5mm | 10/10 |
| December | 7.3°C | 82.1mm | 10/10 |
Full month-by-month guide: best time to visit Brussels →
For facts about Belgium — currency, language and dialling code — see our Belgium country guide at 247CountryInfo. Travellers also find it useful to keep a Brussels travel guide to hand. Check clothing sizes in Belgium before you shop.
Frequently Asked Questions
Is September a good time to visit Brussels?
September rates 10/10 for visiting Brussels — excellent time to visit. Expect average highs of 21.1°C, 68.9mm of rain across the month and about 9.4 hours of daily sunshine.
What is the temperature in Brussels in September?
In September, Brussels has average highs of 21.1°C (70.0°F) and average lows of 12.5°C (54.5°F).
Does it rain in Brussels in September?
Some rain is likely. Brussels averages 68.9mm across about 10 rainy days in September, so a light waterproof layer is worth packing.
What should I wear in Brussels in September?
For Brussels in September (21.1°C highs / 12.5°C lows), pack light layers plus sunscreen, t-shirts and light trousers or shorts, light waterproof layer.
More essentials for Brussels in September
Packing cubes
Keep the bag organised whatever the weather — compression cubes for every size.
Check Price →Travel first aid kit
Compact TSA-friendly kit for peace of mind wherever you travel.
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Climate data sourced from Open-Meteo (open source, open data licence). Monthly averages calculated from 2020–2023 historical data. Weather can be unpredictable — always check a live forecast before travelling.