September weather forecastAalst, Belgium
September
Weather in September
In September, Aalst experiences a slight drop in temperatures, marking the arrival of Autumn. The weather transformation ushers falling leaves and cooler winds into the city. Despite the contract in daylight hours, outdoor events proceed without interruption. Throughout these transitions, the significant drop in rainfall from 32mm (1.26") to 21mm (0.83") remains noteworthy. As the weather settles into comfortable conditions, the wind speed, too, follows a stable pattern.Temperature
With the onset of September, the average high-temperature subtly recedes from August's moderately hot 23.2°C (73.8°F) to an enjoyable 19.8°C (67.6°F). Nighttime temperature in Aalst lowers to an average of 11.2°C (52.2°F) in September.Humidity
The average relative humidity in September in Aalst is 78%.Rainfall
In Aalst, during September, the rain falls for 9.8 days and regularly aggregates up to 21mm (0.83") of precipitation. Throughout the year, there are 169.4 rainfall days, and 421mm (16.57") of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in September in Aalst, Belgium, is 12h and 38min.On the first day of the month, sunrise is at 06:58 and sunset at 20:29. On the last day of September, in Aalst, sunrise is at 07:43 and sunset at 19:23 CEST.
Sunshine
In September, the average sunshine is 7.2h.UV index
In Aalst, Belgium, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Aalst, Belgium
- Average high temperature in September: 19.8°C
The warmest month (with the highest average high temperature) is July (23.3°C).
The month with the lowest average high temperature is January (5.5°C).
- Average low temperature in September: 11.2°C
The month with the highest average low temperature is August (13.8°C).
The coldest month (with the lowest average low temperature) is January (1.3°C).
Average pressure in September
Aalst, Belgium
- Average pressure in September: 1017.3mbar
The month with the highest atmospheric pressure is September (1017.3mbar).
The month with the lowest atmospheric pressure is November (1012.2mbar).
Average wind speed in September
Aalst, Belgium
- Average wind speed in September: 12.1km/h
The windiest month (with the highest average wind speed) is December (17.3km/h).
The calmest month (with the lowest average wind speed) is August (11.7km/h).
Average humidity in September
Aalst, Belgium
- Average humidity in September: 78%
The month with the highest relative humidity is December (88%).
The months with the lowest relative humidity are April, July and August (75%).
Average rainfall in September
Aalst, Belgium
- Average rainfall in September: 21mm
The wettest month (with the highest rainfall) is December (59mm).
The driest month (with the least rainfall) is April (18mm).
Average rainfall days in September
Aalst, Belgium
- Average rainfall days in September: 9.8 days
The month with the highest number of rainy days is December (17.9 days).
The month with the least rainy days is September (9.8 days).
Average snowfall in September
Aalst, Belgium
- Average snowfall in September: 0mm
The month with the highest snowfall is January (36mm).
The months with the least snowfall are April, May, June, July, August, September and October (0mm).
Average snowfall days in September
Aalst, Belgium
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Aalst, Belgium
- Average daylight in September: 12h and 36min
The month with the longest days is June (Average daylight: 16h and 30min).
The month with the shortest days is December (Average daylight: 8h and 0min).
- Average sunshine in September: 7h and 12min
The month with the most sunshine is June (Average sunshine: 9h and 6min).
The month with the least sunshine is December (Average sunshine: 3h and 30min).
Average sunshine days in September
Aalst, Belgium
- Average sunshine days in September: 18.7 days
The month with the most sunshine days is September (18.7 days).
The month with the least sunshine days is February (8.8 days).
Average UV index in September
Aalst, Belgium
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Aalst, Belgium
- Average cloud cover in September: 45
The month with the most cloud cover is December (Cloud cover 64).
The month with the least cloud cover is April (Cloud cover 43).
Average visibility in September
Aalst, Belgium
- Average visibility in September: 9km
The months with the highest visibility are February, March, April, May, June, July, August, September and October (9km).
The months with the lowest visibility are January, November and December (8km).
