Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
September
Weather in September
Temperature
A mild shift in the average high-temperature occurs in September, reducing from an agreeable 22.3°C (72.1°F) in August to a refreshing 18.8°C (65.8°F). Herstal's average low-temperature in the month of September is recorded at a chilly 9.8°C (49.6°F).Humidity
In Herstal, the average relative humidity in September is 80%.Rainfall
In Herstal, in September, during 13.5 rainfall days, 35mm (1.38") of precipitation is typically accumulated. Throughout the year, there are 193.2 rainfall days, and 544mm (21.42") of precipitation is accumulated.Snowfall
May through October are months without snowfall in Herstal, Belgium.Daylight
In September, the average length of the day in Herstal is 12h and 37min.On the first day of September, sunrise is at 06:52 and sunset at 20:22. On the last day of the month, sunrise is at 07:37 and sunset at 19:17 CEST.
Sunshine
The average sunshine in September is 7.8h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Be vigilant - Suggestions to stave off sun damage are provided. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September in Herstal?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September in Herstal?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Herstal, Belgium
- Average high temperature in September: 18.8°C
The warmest months (with the highest average high temperature) are July and August (22.3°C).
The month with the lowest average high temperature is January (4.1°C).
- Average low temperature in September: 9.8°C
The month with the highest average low temperature is August (12.8°C).
The coldest month (with the lowest average low temperature) is January (-0.3°C).
Average pressure in September
Herstal, Belgium
- Average pressure in September: 1017.5mbar
The month with the highest atmospheric pressure is September (1017.5mbar).
The month with the lowest atmospheric pressure is November (1013.1mbar).
Average wind speed in September
Herstal, Belgium
- Average wind speed in September: 10.9km/h
The windiest month (with the highest average wind speed) is December (17km/h).
The calmest month (with the lowest average wind speed) is August (10.5km/h).
Average humidity in September
Herstal, Belgium
- Average humidity in September: 80%
The month with the highest relative humidity is December (89%).
The months with the lowest relative humidity are April and August (77%).
Average rainfall in September
Herstal, Belgium
- Average rainfall in September: 35mm
The wettest month (with the highest rainfall) is December (58mm).
The driest month (with the least rainfall) is April (26mm).
Average rainfall days in September
Herstal, Belgium
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is July (19.4 days).
The month with the least rainy days is February (12.7 days).
Average snowfall in September
Herstal, Belgium
- Average snowfall in September: 0mm
The month with the highest snowfall is January (50mm).
The months with the least snowfall are May, June, July, August, September and October (0mm).
Average snowfall days in September
Herstal, Belgium
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.8 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
Herstal, Belgium
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 24min).
The month with the shortest days is December (Average daylight: 8h and 6min).
- Average sunshine in September: 7h and 5min
The months with the most sunshine are July and August (Average sunshine: 9h and 12min).
The month with the least sunshine is December (Average sunshine: 3h and 36min).
Average sunshine days in September
Herstal, Belgium
- Average sunshine days in September: 13.8 days
The month with the most sunshine days is October (14.7 days).
The month with the least sunshine days is June (8.3 days).
Average UV index in September
Herstal, Belgium
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Herstal, Belgium
- Average cloud cover in September: 42
The month with the most cloud cover is December (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 40).
Average visibility in September
Herstal, Belgium
- Average visibility in September: 8km
The months with the highest visibility are March, April, May, June, July and August (9km).
The months with the lowest visibility are January, February, September, October, November and December (8km).
