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
Rotterdam observes a small decrease in the average high-temperature with the arrival of September, falling from August's pleasant 22°C (71.6°F) to a refreshing 18.7°C (65.7°F). Rotterdam experiences an average low-temperature of 12.8°C (55°F) in month of September.Humidity
In Rotterdam, the average relative humidity in September is 78%.Rainfall
In Rotterdam, Netherlands, in September, it is raining for 9.4 days, with typically 13mm (0.51") of accumulated precipitation. Throughout the year, there are 130.3 rainfall days, and 205mm (8.07") of precipitation is accumulated.Snowfall
In Rotterdam, snow does not fall in April through October.Daylight
In September, the average length of the day is 12h and 39min.On the first day of the month, sunrise is at 06:54 and sunset at 20:28. On the last day of September, in Rotterdam, sunrise is at 07:42 and sunset at 19:21 CEST.
Sunshine
In September, the average sunshine is 7.1h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 4 during September leads to these advisories:
Put precautions into practice - Protective measures against sun-induced damage are advised. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Frequently asked questions
What are the temperatures in Rotterdam in September?
What is the average humidity in September in Rotterdam?
How much does it rain in Rotterdam in September?
When it does not snow in Rotterdam?
How many hours of daylight does Rotterdam have in September?
When is the sunrise / sunset in September in Rotterdam?
How long on average sun shines in September in Rotterdam?
How high is the UV index in September in Rotterdam?
Average temperature in September
Rotterdam, Netherlands
- Average high temperature in September: 18.7°C
The warmest months (with the highest average high temperature) are July and August (22°C).
The month with the lowest average high temperature is January (5.6°C).
- Average low temperature in September: 12.8°C
The month with the highest average low temperature is August (15.3°C).
The coldest month (with the lowest average low temperature) is February (2.3°C).
Average pressure in September
Rotterdam, Netherlands
- Average pressure in September: 1017mbar
The month with the highest atmospheric pressure is September (1017mbar).
The month with the lowest atmospheric pressure is November (1011.4mbar).
Average wind speed in September
Rotterdam, Netherlands
- Average wind speed in September: 14km/h
The windiest month (with the highest average wind speed) is December (20.2km/h).
The calmest months (with the lowest average wind speed) are July and August (13.6km/h).
Average humidity in September
Rotterdam, Netherlands
- Average humidity in September: 78%
The month with the highest relative humidity is December (85%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Rotterdam, Netherlands
- Average rainfall in September: 13mm
The wettest month (with the highest rainfall) is June (24mm).
The driest month (with the least rainfall) is April (9mm).
Average rainfall days in September
Rotterdam, Netherlands
- Average rainfall days in September: 9.4 days
The month with the highest number of rainy days is July (13.8 days).
The month with the least rainy days is February (8.5 days).
Average snowfall in September
Rotterdam, Netherlands
- Average snowfall in September: 0mm
The month with the highest snowfall is February (19mm).
The months with the least snowfall are April, May, June, July, August, September and October (0mm).
Average snowfall days in September
Rotterdam, Netherlands
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.2 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
Rotterdam, Netherlands
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 36min).
The month with the shortest days is December (Average daylight: 7h and 54min).
- Average sunshine in September: 7h and 1min
The month with the most sunshine is June (Average sunshine: 9h and 48min).
The month with the least sunshine is December (Average sunshine: 3h and 30min).
Average sunshine days in September
Rotterdam, Netherlands
- Average sunshine days in September: 17.3 days
The month with the most sunshine days is April (17.5 days).
The month with the least sunshine days is July (13 days).
Average UV index in September
Rotterdam, Netherlands
- 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
Rotterdam, Netherlands
- Average cloud cover in September: 45
The month with the most cloud cover is December (Cloud cover 66).
The month with the least cloud cover is August (Cloud cover 40).
Average visibility in September
Rotterdam, Netherlands
- Average visibility in September: 9km
The months with the highest visibility are April, May, June and August (10km).
The months with the lowest visibility are January, February, March, July, September, October, November and December (9km).
Rotterdam, Netherlands
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