September weather forecastDennison, IL
September
Weather in September
September, the first month of the autumn in Dennison, is still a warm month, with an average temperature fluctuating between 77.4°F (25.2°C) and 58.6°F (14.8°C).Temperature
The advent of September brings an average high-temperature of a still warm 77.4°F (25.2°C), almost identical to the preceding month. Throughout September, Dennison records an average temperature of 58.6°F (14.8°C) at night.Humidity
The average relative humidity in September is 76%.Rainfall
September is the month with the least rainfall. Rain falls for 12.5 days and accumulates 1.81" (46mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, sunrise is at 6:19 am and sunset at 7:20 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:33 pm CDT.
Sunshine
In September, the average sunshine is 8.4h.UV index
In Dennison, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. When the Sun is at its strongest around midday, find shade and limit exposure. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Dennison, IL
- Average high temperature in September: 77.4°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (34.3°F).
- Average low temperature in September: 58.6°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 (22.3°F).
Average pressure in September
Dennison, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Dennison, IL
- Average wind speed in September: 6.8mph
The windiest month (with the highest average wind speed) is February (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in September
Dennison, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Dennison, IL
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is April (4.96").
The driest month (with the least rainfall) is September (1.81").
Average rainfall days in September
Dennison, IL
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (20.6 days).
The month with the least rainy days is January (8.2 days).
Average snowfall in September
Dennison, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.56").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Dennison, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Dennison, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 8h and 24min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The months with the least sunshine are January and December (Average sunshine: 4h and 18min).
Average sunshine days in September
Dennison, IL
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is May (7.9 days).
Average UV index in September
Dennison, IL
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in September
Dennison, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are June, August and September (Cloud cover 32).
Average visibility in September
Dennison, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
