September weather forecast
Flossmoor, IL

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Weather in September

September, the first month of the autumn in Flossmoor, is still a warm month, with an average temperature fluctuating between 58.3°F (14.6°C) and 73.9°F (23.3°C).

Temperature

Flossmoor's progression into September involves a gentle drop in the average high-temperature, from 80.1°F (26.7°C) in August to a still warm 73.9°F (23.3°C). An average nighttime temperature of 58.3°F (14.6°C) is recorded during September.

Humidity

In September, the average relative humidity is 76%.

Rainfall

In Flossmoor, in September, during 13.4 rainfall days, 2.48" (63mm) of precipitation is typically accumulated. Throughout the year, in Flossmoor, there are 155.6 rainfall days, and 31.3" (795mm) of precipitation is accumulated.

Snowfall

In Flossmoor, Illinois, snow does not fall in May through September.

Daylight

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, in Flossmoor, Illinois, sunrise is at 6:47 am and sunset at 6:33 pm CDT.

Sunshine

In Flossmoor, the average sunshine in September is 8.8h.

UV index

The average daily maximum UV index in September in Flossmoor is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Ensure safety - Recommendations to avert sunburn are presented. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Enhance your sun protection with tightly woven, yet airy clothing.
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Frequently asked questions

What is the usual temperature for Flossmoor in September?

The average high-temperature and low-temperature in Flossmoor, Illinois, during September are 73.9°F (23.3°C) and 58.3°F (14.6°C) respectively. The average heat index (a.k.a. 'feels like', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, in July is evaluated at 87.8°F (31°C).

What is the average humidity in September in Flossmoor?

In Flossmoor, Illinois, the average relative humidity in September is 76%.

How many days does it rain in September in Flossmoor?

In Flossmoor, in September, during 13.4 rainfall days, 2.48" (63mm) of precipitation is typically accumulated.

When it does not snow in Flossmoor?

In Flossmoor, Illinois, snow does not fall in May through September.

Does it snow in Flossmoor in September?

In Flossmoor, Illinois, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Flossmoor have in September?

In Flossmoor, the average day length in September is 12h and 28min.

When are sunrise and sunset in September in Flossmoor?

In September, on the first day of the month, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of the month, in Flossmoor, Illinois, sunrise is at 6:47 am and sunset at 6:33 pm CDT.

How many hours of sunshine does Flossmoor have in September?

In September, the average sunshine duration is 8.8h.

How high is the UV index in September in Flossmoor?

The average daily maximum UV index in September in Flossmoor is 4. A UV Index reading of 3 to 5 represents a medium health risk from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Flossmoor, IL

Average temperature in September - Flossmoor, 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).

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Average pressure in September
Flossmoor, IL

Average pressure in September - Flossmoor, 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).

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Average wind speed in September
Flossmoor, IL

Average wind speed in September - Flossmoor, 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).

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Average humidity in September
Flossmoor, IL

Average humidity in September - Flossmoor, 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%).

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Average rainfall in September
Flossmoor, IL

Average rainfall in September - Flossmoor, 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").

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Average rainfall days in September
Flossmoor, IL

Average rainfall days in September - Flossmoor, 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).

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Average snowfall in September
Flossmoor, IL

Average snowfall in September - Flossmoor, 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").

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Average snowfall days in September
Flossmoor, IL

Average snowfall days in September - Flossmoor, 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).

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Average daylight in September /
Average sunshine in September
Flossmoor, IL

Average daylight in September / Average sunshine in September - Flossmoor, 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 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).

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Average sunshine days in September
Flossmoor, IL

Average sunshine days in September - Flossmoor, 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).

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Average UV index in September
Flossmoor, IL

Average UV index in September - Flossmoor, 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).

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Average cloud cover in September
Flossmoor, IL

Average cloud cover in September - Flossmoor, 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).

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Average visibility in September
Flossmoor, IL

Average visibility in September - Flossmoor, 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).

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Flossmoor, Illinois, USA

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