Weather in Brussels for September 2025
In general, the average temperature in Brussels at the beginning of September is 25.4 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 18.1 °C by the end of September.
Brussels sees moderate rainfall in September, averaging 8 rainy days.
Is September a good time to visit Brussels? check out the best time to travel to Brussels page.
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Brussels in September average weather
| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  26° | 2 26° | 3  24° | 4  24° | 5 25° | 6 24° | 7 29° |
| 8 26° | 9 24° | 10 24° | 11  21° | 12  19° | 13 18° | 14  20° |
| 15  22° | 16 22° | 17 23° | 18 24° | 19 22° | 20 22° | 21  22° |
| 22 20° | 23 18° | 24 18° | 25 18° | 26 20° | 27 19° | 28 17° |
| 29 18° | 30 17° |
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Temperatures trend during September in Brussels
September weather day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Light rain shower | 26° /15° | 20 mm | 7 | |
| 2 Sept. | Patchy rain possible | 26° /16° | 2.4 mm | 6 | |
| 3 Sept. | Mist | 24° /16° | 0.1 mm | 5 | |
| 4 Sept. | Sunny | 24° /14° | 0.8 mm | 6 | |
| 5 Sept. | Sunny | 25° /15° | 6.1 mm | 6 | |
| 6 Sept. | Sunny | 24° /15° | 2.3 mm | 6 | |
| 7 Sept. | Sunny | 29° /14° | 0.3 mm | 8 | |
| 8 Sept. | Sunny | 26° /16° | 1.9 mm | 7 | |
| 9 Sept. | Sunny | 24° /15° | 3.8 mm | 6 | |
| 10 Sept. | Sunny | 24° /15° | 1.3 mm | 6 | |
| 11 Sept. | Moderate rain at times | 21° /14° | 4.6 mm | 5 | |
| 12 Sept. | Overcast | 19° /11° | 0.9 mm | 4 | |
| 13 Sept. | Mist | 18° /10° | 1.1 mm | 5 | |
| 14 Sept. | Cloudy | 20° /12° | 0.1 mm | 5 | |
| 15 Sept. | Partly cloudy | 22° /10° | 0 mm | 5 | |
| 16 Sept. | Sunny | 22° /12° | 0.4 mm | 6 | |
| 17 Sept. | Patchy rain possible | 23° /14° | 0.9 mm | 5 | |
| 18 Sept. | Patchy rain possible | 24° /14° | 0.5 mm | 6 | |
| 19 Sept. | Patchy rain possible | 22° /13° | 0 mm | 6 | |
| 20 Sept. | Cloudy | 22° /13° | 0 mm | 6 | |
| 21 Sept. | Moderate rain | 22° /12° | 8.7 mm | 5 | |
| 22 Sept. | Light rain shower | 20° /12° | 1.5 mm | 5 | |
| 23 Sept. | Patchy rain possible | 18° /11° | 7 mm | 4 | |
| 24 Sept. | Partly cloudy | 18° /10° | 1.2 mm | 5 | |
| 25 Sept. | Overcast | 18° /11° | 9.9 mm | 4 | |
| 26 Sept. | Partly cloudy | 20° /13° | 3.4 mm | 5 | |
| 27 Sept. | Partly cloudy | 19° /11° | 3 mm | 5 | |
| 28 Sept. | Partly cloudy | 17° /10° | 2.3 mm | 5 | |
| 29 Sept. | Light rain shower | 18° /8° | 0.7 mm | 4 | |
| 30 Sept. | Partly cloudy | 17° /9° | 2.4 mm | 4 | |
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Guide for Brussels in September
In September, Brussels, Belgium experiences a transition from the lingering warmth of summer to the cooler temperatures of autumn. At the beginning of the month, the weather in Brussels is generally mild and pleasant, with average temperatures around 16°.
The city experiences a mix of sunny days and occasional rainfall, with an average of 14 rainy days throughout the month. As September progresses, the temperatures gradually begin to decrease, and by the end of the month, the average temperature in Brussels hovers around 13°.
The evenings become notably cooler, making it advisable for visitors to bring a light jacket or sweater when exploring the city after sunset.
The weather in Brussels during September is characterized by a comfortable and temperate climate, making it an ideal time to explore the city's charming streets, parks, and historic landmarks.
However, visitors should be prepared for the possibility of occasional showers, especially towards the end of the month. Overall, September offers a pleasant and inviting atmosphere for travelers to enjoy the cultural delights of Brussels.
Brussels in September - FAQ
What to pack to Brussels in September?
As you prepare for your trip to Brussels in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in Brussels, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Warm Clothing: Sweaters, hoodies, long pants
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Accessories
- Sunglasses: For sun protection
- Sun Hats: Wide-brimmed hats for sun protection in warm weather
- Scarves: To protect you from the cold wind
- Gloves/Mittens: Essential for cold weather
- Warm Hats: Warm hats for insulation in cold weather
- Umbrellas/Raincoats: For rainy days
September rainfall patterns in Brussels
UV exposure in Brussels during September
Quick links
Where is Brussels?Get accurate weather forecasts for Brussels, located at latitude 50.85 and longitude 4.349. Stay updated with localized weather information tailored for Brussels.