September weather forecastFrankfort Square, IL
September
Weather in September
September, the first month of the autumn in Frankfort Square, is still a warm month, with temperature in the range of an average low of 57.9°F (14.4°C) and an average high of 73.9°F (23.3°C).Temperature
September's onset corresponds with a subtle shift in the average high-temperature, slightly moving from a moderately hot 79.9°F (26.6°C) in August to a still warm 73.9°F (23.3°C). Frankfort Square experiences an average temperature drop to a mild 57.9°F (14.4°C) during September nights.Humidity
In September, the average relative humidity is 76%.Rainfall
In Frankfort Square, in September, it is raining for 10.4 days, with typically 0.98" (25mm) of accumulated precipitation. In Frankfort Square, during the entire year, the rain falls for 111.8 days and collects up to 11.18" (284mm) of precipitation.Snowfall
In Frankfort Square, snow does not fall in May through September.Daylight
In September, the average length of the day in Frankfort Square is 12h and 28min.On the first day of the month, sunrise is at 6:18 am and sunset at 7:23 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:34 pm CDT.
Sunshine
In Frankfort Square, 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 threat to health from unsafe exposure to UV radiation for the average person.Note: A typical high UV index of 4 in September suggests the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. Direct Sun exposure should be minimized especially during midday when radiation is most intense. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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 0min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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
Frankfort Square, 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).





