September weather forecastTroy, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Troy, Illinois, with an average temperature ranging between min 59.9°F (15.5°C) and max 79°F (26.1°C).Temperature
Troy marks the onset of September with an average high-temperature of a still moderately hot 79°F (26.1°C), subtly divergent from August's 84°F (28.9°C). Throughout September, the nighttime temperature averages to a refreshing 59.9°F (15.5°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In Troy, Illinois, during September, the rain falls for 12.3 days and regularly aggregates up to 2.13" (54mm) of precipitation. In Troy, during the entire year, the rain falls for 149.9 days and collects up to 33.94" (862mm) of precipitation.Snowfall
Months with snowfall are January through March, September, November and December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In Troy, during the entire year, snow falls for 20.7 days and aggregates up to 7.13" (181mm) of snow.Daylight
In Troy, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:43 pm CDT.
Sunshine
In September, the average sunshine is 9.3h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: A maximum high daily UV index of 5 during September translates into the following directions:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Troy, IL
- Average high temperature in September: 79°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Troy, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Troy, IL
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is January (9.5mph).
The calmest month (with the lowest average wind speed) is July (5.6mph).
Average humidity in September
Troy, IL
- Average humidity in September: 75%
The months with the highest relative humidity are May, July and August (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Troy, IL
- Average rainfall in September: 2.13"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is February (1.77").
Average rainfall days in September
Troy, IL
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in September
Troy, IL
- Average snowfall in September: 0.04"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in September
Troy, IL
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (7 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Troy, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 18min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Troy, IL
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is December (18.6 days).
The month with the least sunshine days is May (11.6 days).
Average UV index in September
Troy, IL
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Troy, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are June and August (Cloud cover 28).
Average visibility in September
Troy, 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).





