September weather forecastLibertyville, IL
September
Weather in September
September, the first month of the autumn in Libertyville, is also an agreeable month, with an average temperature varying between 57.7°F (14.3°C) and 72°F (22.2°C).Temperature
September brings a slight decrease in temperature, down from a moderately hot 78.6°F (25.9°C) in August to a pleasant 72°F (22.2°C). Throughout September, the temperature tends to fall to a consistent average low of 57.7°F (14.3°C).Humidity
The average relative humidity in September in Libertyville is 76%.Rainfall
In Libertyville, in September, it is raining for 12.5 days, with typically 1.54" (39mm) of accumulated precipitation. In Libertyville, during the entire year, the rain falls for 142.1 days and collects up to 20.67" (525mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:17 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:34 pm CDT.
Sunshine
In September, the average sunshine is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: In September, a regular UV index of 4 translates into these guidelines:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. The Sun's radiation is especially intense around midday; try to stay in shade during this period. 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
Libertyville, IL
- Average high temperature in September: 72°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (27.9°F).
- Average low temperature in September: 57.7°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (17.2°F).
Average pressure in September
Libertyville, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Libertyville, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in September
Libertyville, IL
- Average humidity in September: 76%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Libertyville, IL
- Average rainfall in September: 1.54"
The wettest month (with the highest rainfall) is June (2.56").
The driest month (with the least rainfall) is December (0.87").
Average rainfall days in September
Libertyville, IL
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is July (17.5 days).
The month with the least rainy days is February (4.4 days).
Average snowfall in September
Libertyville, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.07").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Libertyville, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Libertyville, 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 6min).
- Average sunshine in September: 9h and 0min
The months with the most sunshine are July and August (Average sunshine: 10h and 18min).
The months with the least sunshine are January and February (Average sunshine: 3h and 48min).
Average sunshine days in September
Libertyville, IL
- Average sunshine days in September: 13.8 days
The month with the most sunshine days is November (17 days).
The month with the least sunshine days is July (10.8 days).
Average UV index in September
Libertyville, IL
- Average UV index in September: 4
The months with the highest UV index are 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
Libertyville, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in September
Libertyville, 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).
