Spa Weather in September
In Spa, September brings pleasant daytime temperatures around 19°C (66°F), with nights cooling to 10°C (50°F). Expect quite a bit of rainfall this month.
Rainfall in Spa in September
Typically, you can expect about 17 days of rain this month, with 85 mm (3.3 in) on average. A fairly balanced picture this month, some wet days but nothing too extreme in terms of intensity.
Temperature in Spa in September
September in Spa sees highs of 19°C (66°F) and lows of 10°C (50°F) overnight. Conditions are often most pleasant around the middle of the day. At 10°C (50°F) overnight, it gets properly cold after dark. On the bright side, cold nights tend to make for excellent sleeping conditions.
Sunshine in Spa in September
You can expect a moderate amount of sunlight, with approximately 160 hours. This means a pleasant mix of sun and overcast.
Wind Speed in Spa in September
Wind speeds average 4 m/s (8 knots) during September. At this speed, expect moderate winds that can raise dust and move small branches. Since this is an average, some days have gentle light winds while others experience stronger breezes that are quite noticeable.For Spa itself, June and August generally stand out with the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.
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 Spa's climate page.
Spa Temperature in September
Min Temperature
10°C (50°F)
Max Temperature
19°C (66°F)
Chance of Rain
56%
Precipitation
85 mm (3.3 in)
Rainy days
17 days
Humidity
88% *
Windspeed
4 m/s (8 knots) *
Sunshine
160 hours *
Percentage Sunshine
*
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Spa typically stay consistent throughout September, with daily highs averaging around 19°C (66°F). Nights are cool, with lows typically ranging from 8°C (46°F) to 10°C (50°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 Spa in September
Browse day-by-day weather records for Spa spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Spa historical weather extremes in September
Based on 49 years of weather observations in Spa between 1976 and 2025, these are the recorded extremes.
- On September 15, 2020, temperatures climbed to 31°C (88°F), marking the warmest September day on record.
- Spa experienced its chilliest September day on September 25, 2025, reaching only 7°C (45°F).
- The lowest overnight temperature recorded in September was 0°C (32°F) (September 28, 1987).
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
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What to Wear in Spa in September
For Spa in September, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho. It won't hurt to bring your sunglasses along, as you'll see some sunny periods.What To Do in Spa 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 Spa's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed
See the full Spa climate overview or explore weather in Belgium.
