September weather forecastStreamwood, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Streamwood, Illinois, with an average temperature fluctuating between 56.8°F (13.8°C) and 73.4°F (23°C).Temperature
September's onset corresponds with a subtle shift in the average high-temperature, slightly moving from a moderately hot 79.9°F (26.6°C) in August to a still warm 73.4°F (23°C). In the month of September, the temperature generally rests at an average low of 56.8°F (13.8°C).Humidity
In September, the average relative humidity is 76%.Rainfall
In Streamwood, in September, it is raining for 12.5 days, with typically 1.65" (42mm) of accumulated precipitation. Throughout the year, there are 141.5 rainfall days, and 22.76" (578mm) of precipitation is accumulated.Snowfall
In Streamwood, snow does not fall in June through September.Daylight
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
The average sunshine in September is 8.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Make use of precautions - Suggestions to resist sunburn are communicated. When the Sun is at its strongest around midday, find shade and limit exposure. 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
Average temperature in September
Streamwood, IL
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (27.7°F).
- Average low temperature in September: 56.8°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 (16.3°F).
Average pressure in September
Streamwood, 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
Streamwood, IL
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Streamwood, 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
Streamwood, IL
- Average rainfall in September: 1.65"
The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is December (1.02").
Average rainfall days in September
Streamwood, IL
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is July (17.4 days).
The month with the least rainy days is February (4.8 days).
Average snowfall in September
Streamwood, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.39").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Streamwood, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Streamwood, IL
- Average daylight in September: 12h and 30min
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 36min
The months with the most sunshine are July and August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Streamwood, IL
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is November (17.6 days).
The month with the least sunshine days is July (10.9 days).
Average UV index in September
Streamwood, 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
Streamwood, IL
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July, August and September (Cloud cover 33).
Average visibility in September
Streamwood, IL
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
