Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The arrival of September corresponds with a light shift in temperature, down from 79.9°F (26.6°C) in August to a still moderately hot 73.9°F (23.3°C). During September, an average low-temperature of 57.9°F (14.4°C) is observed in Oak Forest.Humidity
In September, the average relative humidity is 76%.Rainfall
In September, the rain falls for 10.4 days. Throughout September, 0.98" (25mm) of precipitation is accumulated. In Oak Forest, during the entire year, the rain falls for 111.8 days and collects up to 11.18" (284mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September in Oak Forest is 12h and 28min.On the first day of September, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:33 pm CDT.
Sunshine
The average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum UV index of 4 in September translates into the following recommendations:
Put precautions into practice - Ensuring skin and eye safety is a necessity. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Oak Forest have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Oak Forest have in September?
What is the UV index reading in September in Oak Forest?
Average temperature in September
Oak Forest, IL
- Average high temperature in September: 73.9°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in September: 57.9°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 (18.7°F).
Average pressure in September
Oak 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
Oak Forest, IL
- Average wind speed in September: 7.2mph
The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Oak Forest, IL
- Average humidity in September: 76%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Oak Forest, IL
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is May (1.54").
The driest months (with the least rainfall) are January, February and December (0.55").
Average rainfall days in September
Oak Forest, IL
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is July (14.1 days).
The month with the least rainy days is February (4.1 days).
Average snowfall in September
Oak Forest, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.3").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Oak Forest, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.3 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
Oak Forest, IL
- Average daylight in September: 12h and 3min
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 5min
The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Oak Forest, IL
- Average sunshine days in September: 17 days
The month with the most sunshine days is November (20.7 days).
The month with the least sunshine days is June (13.1 days).
Average UV index in September
Oak Forest, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Oak Forest, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Oak Forest, 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).
Oak Forest, Illinois, USA
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