September weather forecastPark Forest, IL
September
Weather in September
September, the first month of the autumn in Park Forest, is also a moderately hot month, with an average temperature ranging between min 58.3°F (14.6°C) and max 73.9°F (23.3°C).Temperature
September is characterized by a mild reduction in the average high-temperature, from 80.1°F (26.7°C) in August to a still moderately hot 73.9°F (23.3°C). Throughout the September nights, Park Forest encounters a low-temperature of 58.3°F (14.6°C).Humidity
In Park Forest, the average relative humidity in September is 76%.Rainfall
In Park Forest, during September, the rain falls for 13.4 days and regularly aggregates up to 2.48" (63mm) of precipitation. In Park Forest, during the entire year, the rain falls for 155.6 days and collects up to 31.3" (795mm) of precipitation.Snowfall
In Park Forest, snow does not fall in May through September.Daylight
In Park Forest, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:33 pm CDT.
Sunshine
In Park Forest, the average sunshine in September is 8.8h.UV index
In Park Forest, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.Note: The UV index of 4 during September leads to these advisories:
Adopt protective measures - Suggestions to resist sunburn are offered. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Park Forest, IL
- Average high temperature in September: 73.9°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.7°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 (18.9°F).
Average pressure in September
Park Forest, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Park Forest, IL
- Average wind speed in September: 7.3mph
The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in September
Park Forest, IL
- Average humidity in September: 76%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Park Forest, IL
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is December (1.54").
Average rainfall days in September
Park Forest, IL
- Average rainfall days in September: 13.4 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (6.1 days).
Average snowfall in September
Park Forest, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Park Forest, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Park Forest, 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: 8h and 48min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Park Forest, IL
- Average sunshine days in September: 14 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.2 days).
Average UV index in September
Park Forest, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Park Forest, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Park Forest, IL
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





