September weather forecastForest City, IL
September
Weather in September
September, the first month of the autumn in Forest City, is also a moderately hot month, with an average temperature ranging between max 76.6°F (24.8°C) and min 58.3°F (14.6°C).Temperature
The advent of September signifies a minor shift to an average high-temperature of a still moderately hot 76.6°F (24.8°C), aligning closely with August. An average low-temperature of 58.3°F (14.6°C) is recorded during the nights in September.Humidity
The average relative humidity in September in Forest City is 75%.Rainfall
In Forest City, Illinois, in September, during 13 rainfall days, 2.68" (68mm) of precipitation is typically accumulated. Throughout the year, in Forest City, there are 162.3 rainfall days, and 32.72" (831mm) of precipitation is accumulated.Snowfall
In Forest City, Illinois, snow does not fall in May through September.Daylight
In September, the average length of the day in Forest City is 12h and 27min.On the first day of the month, sunrise is at 6:27 am and sunset at 7:30 pm. On the last day of September, in Forest City, sunrise is at 6:55 am and sunset at 6:42 pm CDT.
Sunshine
The average sunshine in September is 9.3h.UV index
In Forest City, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 5 suggests these recommendations:
Exercise prevention - Protecting skin and eyes from harm is required. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Boost your sun resistance with garments that are densely woven yet spacious.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Forest City, IL
- Average high temperature in September: 76.6°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (31.5°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 (19.8°F).
Average pressure in September
Forest City, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Forest City, IL
- Average wind speed in September: 7.4mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in September
Forest City, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Forest City, IL
- Average rainfall in September: 2.68"
The wettest month (with the highest rainfall) is May (4.49").
The driest month (with the least rainfall) is January (1.73").
Average rainfall days in September
Forest City, IL
- Average rainfall days in September: 13 days
The month with the highest number of rainy days is May (20.3 days).
The month with the least rainy days is February (6.5 days).
Average snowfall in September
Forest City, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.25").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Forest City, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Forest City, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 18min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Forest City, IL
- Average sunshine days in September: 15.2 days
The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is July (8.5 days).
Average UV index in September
Forest City, 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, November and December (UV index 2).
Average cloud cover in September
Forest City, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is September (Cloud cover 29).
Average visibility in September
Forest City, 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).





