September weather forecastHaarlem, Netherlands
September
Weather in September
In September, Haarlem, begins to transition away from the summer radiance, with temperatures dipping to around 17.7°C (63.9°F). Signs of autumn's arrival start emerging as leaves turn hues and fall. However, the afternoons continue to retain some warmth, creating a unique combination of conditions. Frequent drizzles characterize September, adding to the charm of the transforming season. As autumn encroaches, September weather successfully balances the receding summer heat with the arriving chill of the fall season.Temperature
The arrival of September is marked by an average high-temperature of a still comfortable 17.7°C (63.9°F), bearing a close resemblance to August. Haarlem registers a steady nighttime temperature averaging a still refreshing 14.5°C (58.1°F) throughout September.Humidity
In September, the average relative humidity is 77%.Rainfall
In Haarlem, in September, during 15.2 rainfall days, 36mm (1.42") of precipitation is typically accumulated. Throughout the year, there are 169.2 rainfall days, and 339mm (13.35") of precipitation is accumulated.Snowfall
April through November are months without snowfall in Haarlem.Daylight
In Haarlem, the average length of the day in September is 12h and 40min.On the first day of September, sunrise is at 06:53 and sunset at 20:28. On the last day of the month, sunrise is at 07:41 and sunset at 19:20 CEST.
Sunshine
In Haarlem, the average sunshine in September is 7h.UV index
The average daily maximum UV index in September in Haarlem is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.Note: A daily high UV index of 4 in September leads to these guidelines:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. To protect against the Sun's most potent rays, avoid direct exposure around midday. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Haarlem, Netherlands
- Average high temperature in September: 17.7°C
The warmest month (with the highest average high temperature) is August (19.9°C).
The months with the lowest average high temperature are January and February (5.8°C).
- Average low temperature in September: 14.5°C
The month with the highest average low temperature is August (16.6°C).
The coldest month (with the lowest average low temperature) is February (3.3°C).
Average pressure in September
Haarlem, Netherlands
- Average pressure in September: 1016.6mbar
The month with the highest atmospheric pressure is September (1016.6mbar).
The month with the lowest atmospheric pressure is November (1010.9mbar).
Average wind speed in September
Haarlem, Netherlands
- Average wind speed in September: 20.3km/h
The windiest month (with the highest average wind speed) is December (28.4km/h).
The calmest month (with the lowest average wind speed) is July (18km/h).
Average humidity in September
Haarlem, Netherlands
- Average humidity in September: 77%
The months with the highest relative humidity are January and December (83%).
The month with the lowest relative humidity is August (76%).
Average rainfall in September
Haarlem, Netherlands
- Average rainfall in September: 36mm
The wettest month (with the highest rainfall) is August (48mm).
The driest month (with the least rainfall) is April (11mm).
Average rainfall days in September
Haarlem, Netherlands
- Average rainfall days in September: 15.2 days
The month with the highest number of rainy days is August (17.2 days).
The month with the least rainy days is April (10.6 days).
Average snowfall in September
Haarlem, Netherlands
- Average snowfall in September: 0mm
The month with the highest snowfall is February (9mm).
The months with the least snowfall are April, May, June, July, August, September, October and November (0mm).
Average snowfall days in September
Haarlem, Netherlands
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.7 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Haarlem, Netherlands
- Average daylight in September: 12h and 42min
The month with the longest days is June (Average daylight: 16h and 42min).
The month with the shortest days is December (Average daylight: 7h and 48min).
- Average sunshine in September: 7h and 0min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is December (Average sunshine: 3h and 24min).
Average sunshine days in September
Haarlem, Netherlands
- Average sunshine days in September: 11.4 days
The month with the most sunshine days is April (17.7 days).
The month with the least sunshine days is December (9.1 days).
Average UV index in September
Haarlem, 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
Haarlem, Netherlands
- Average cloud cover in September: 46
The month with the most cloud cover is December (Cloud cover 67).
The month with the least cloud cover is August (Cloud cover 39).
Average visibility in September
Haarlem, Netherlands
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October and November (10km).
The month with the lowest visibility is December (9km).
