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
The arrival of September signals a subtle shift in temperature, down from 80.1°F (26.7°C) in August to a still moderately hot 73.9°F (23.3°C). Throughout September, Flossmoor encounters an average temperature drop to a moderate 58.3°F (14.6°C).Humidity
The average relative humidity in September is 76%.Rainfall
In Flossmoor, in September, during 13.4 rainfall days, 2.48" (63mm) of precipitation is typically accumulated. In Flossmoor, during the entire year, the rain falls for 155.6 days and collects up to 31.3" (795mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:33 pm CDT.
Sunshine
In Flossmoor, Illinois, the average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index in Flossmoor is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The daily high UV index of 4 in September translates into this advice:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. When the Sun is at its strongest around midday, find shade and limit exposure. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Flossmoor in September?
What is the average humidity in September in Flossmoor?
How many days does it rain in September in Flossmoor?
When it does not snow?
Does it snow in September?
How many hours of daylight does Flossmoor have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Flossmoor have in September?
What is the UV index reading in September?
Average temperature in September
Flossmoor, IL
- Average high temperature in September: 73.9°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 (29.7°F).
- Average low temperature in September: 58.3°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Flossmoor, 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
Flossmoor, IL
- Average wind speed in September: 7.3mph
The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in September
Flossmoor, IL
- Average humidity in September: 76%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Flossmoor, IL
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is December (1.54").
Average rainfall days in September
Flossmoor, IL
- Average rainfall days in September: 13.4 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (6.1 days).
Average snowfall in September
Flossmoor, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Flossmoor, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Flossmoor, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Flossmoor, IL
- Average sunshine days in September: 14 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.2 days).
Average UV index in September
Flossmoor, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Flossmoor, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Flossmoor, IL
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Flossmoor, Illinois, USA
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