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
Weather in September
Temperature
September marks a gentle change in average high-temperature in Herstal, declining from August's agreeable 22.3°C (72.1°F) to a refreshing 18.8°C (65.8°F). Herstal's nighttime temperature in September drops to an average of 9.8°C (49.6°F).Humidity
In Herstal, the average relative humidity in September is 80%.Rainfall
In September, the rain falls for 13.5 days. Throughout September, 35mm (1.38") of precipitation is accumulated. In Herstal, during the entire year, the rain falls for 193.2 days and collects up to 544mm (21.42") of precipitation.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September is 12h and 37min.On the first day of the month, sunrise is at 06:52 and sunset at 20:22. On the last day of September, sunrise is at 07:37 and sunset at 19:17 CEST.
Sunshine
In Herstal, the average sunshine in September is 7.8h.UV index
The average daily maximum UV index in September in Herstal is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Herstal?
What is the average humidity in September in Herstal?
How much does it rain in Herstal in September?
When it does not snow in Herstal?
How many hours of daylight does Herstal have in September?
When are sunrise and sunset in September in Herstal?
How long on average sun shines in September in Herstal?
What is the UV index intensity in September in Herstal?
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).
Herstal, Belgium
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