September weather forecastSilvis, IL
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Silvis, Illinois, with an average temperature ranging between min 56.3°F (13.5°C) and max 75.4°F (24.1°C).Temperature
Entering September, the average high-temperature is recorded at a still warm 75.4°F (24.1°C), exhibiting a minimal shift from August's 80.6°F (27°C). An average low-temperature of 56.3°F (13.5°C) is recorded in the month of September.Humidity
In Silvis, the average relative humidity in September is 76%.Rainfall
In Silvis, during September, the rain falls for 6.9 days and regularly aggregates up to 0.75" (19mm) of precipitation. Throughout the year, there are 99.4 rainfall days, and 9.57" (243mm) of precipitation is accumulated.Snowfall
January through April, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 24.5 snowfall days, and 4.09" (104mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September, sunrise is at 6:28 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:44 pm CDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. 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
Silvis, IL
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (15.4°F).
Average pressure in September
Silvis, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Silvis, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in September
Silvis, IL
- Average humidity in September: 76%
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Silvis, IL
- Average rainfall in September: 0.75"
The wettest month (with the highest rainfall) is May (1.61").
The driest month (with the least rainfall) is December (0.35").
Average rainfall days in September
Silvis, IL
- Average rainfall days in September: 6.9 days
The month with the highest number of rainy days is May (13.4 days).
The month with the least rainy days is January (3.2 days).
Average snowfall in September
Silvis, IL
- Average snowfall in September: 0.04"
The month with the highest snowfall is January (1.26").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Silvis, IL
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (7.2 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Silvis, IL
- Average daylight in September: 12h and 30min
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: 9h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Silvis, IL
- Average sunshine days in September: 20.9 days
The month with the most sunshine days is December (22.4 days).
The month with the least sunshine days is June (14.4 days).
Average UV index in September
Silvis, IL
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Silvis, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Silvis, 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).





