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
In September, the average high-temperature marginally drops from 80.2°F (26.8°C) in August to a still warm 73.6°F (23.1°C). Throughout September, the temperature falls to an average low of 57.2°F (14°C).Humidity
In September, the average relative humidity is 76%.Rainfall
In Carol Stream, Illinois, during September, the rain falls for 10.3 days and regularly aggregates up to 0.83" (21mm) of precipitation. In Carol Stream, during the entire year, the rain falls for 119.1 days and collects up to 10.83" (275mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In Carol Stream, the average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:19 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:35 pm CDT.
Sunshine
In September, the average sunshine is 8.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the average person.Note: The daily high UV index of 4 in September translates into this advice:
Take precautions - Protection against sun damage is advised. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
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
Carol Stream, IL
- Average high temperature in September: 73.6°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (27.9°F).
- Average low temperature in September: 57.2°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (16.7°F).
Average pressure in September
Carol Stream, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Carol Stream, IL
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is January (9.8mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in September
Carol Stream, IL
- Average humidity in September: 76%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Carol Stream, IL
- Average rainfall in September: 0.83"
The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are February, November and December (0.51").
Average rainfall days in September
Carol Stream, IL
- Average rainfall days in September: 10.3 days
The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Carol Stream, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.5").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Carol Stream, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Carol Stream, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 5min
The months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Carol Stream, IL
- Average sunshine days in September: 16.6 days
The month with the most sunshine days is November (20.6 days).
The month with the least sunshine days is July (11.3 days).
Average UV index in September
Carol Stream, IL
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Carol Stream, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July, August and September (Cloud cover 32).
Average visibility in September
Carol Stream, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Carol Stream, Illinois, USA
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