September weather forecast
Grant Park, IL

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Grant Park, Illinois, with temperature in the range of an average high of 74.8°F (23.8°C) and an average low of 56.8°F (13.8°C).

Temperature

The dawn of September sees an average high-temperature of a still warm 74.8°F (23.8°C), subtly contrasting with August's 79.7°F (26.5°C). Grant Park experiences an average low-temperature reading of 56.8°F (13.8°C) throughout September.

Humidity

In September, the average relative humidity in Grant Park is 78%.

Rainfall

In September, the rain falls for 11.6 days. Throughout September, 1.1" (28mm) of precipitation is accumulated. Throughout the year, there are 132 rainfall days, and 15.16" (385mm) of precipitation is accumulated.

Snowfall

In Grant Park, snow does not fall in May through October.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of September in Grant Park, sunrise is at 6:17 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:33 pm CDT.

Sunshine

In Grant Park, the average sunshine in September is 8.7h.

UV index

In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for the ordinary person.
Note: An average UV index of 5 in September transforms into this advice:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
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Frequently asked questions

What is the temperature in September in Grant Park?

An average high-temperature, in September, in Grant Park, is 74.8°F (23.8°C) and the average low-temperature is 56.8°F (13.8°C). The average heat index (a.k.a. 'real feel', 'feels like'), which combines air temperature and relative humidity, in July is evaluated at 87.8°F (31°C).

What is the average humidity in September in Grant Park?

In September, the average relative humidity in Grant Park, Illinois, is 78%.

How much does it rain in Grant Park in September?

In Grant Park, in September, during 11.6 rainfall days, 1.1" (28mm) of precipitation is typically accumulated.

When it does not snow in Grant Park?

In Grant Park, snow does not fall in May through October.

How many hours of daylight does Grant Park have in September?

In Grant Park, Illinois, the average day length in September is 12h and 28min.

What time are sunrise and sunset in September in Grant Park?

In September, on the first day of the month, sunrise is at 6:17 am and sunset at 7:22 pm. On the last day of the month, in Grant Park, Illinois, sunrise is at 6:47 am and sunset at 6:33 pm CDT.

How many hours of sunshine does Grant Park have in September?

In September, the average sunshine duration is 8.7h.

What is the UV index reading in September in Grant Park?

In Grant Park, Illinois, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium health risk from exposure to the Sun's UV radiation.
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
Grant Park, IL

Average temperature in September - Grant Park, IL
  • Average high temperature in September: 74.8°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (30°F).

  • Average low temperature in September: 56.8°F

The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).

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Average pressure in September
Grant Park, IL

Average pressure in September - Grant Park, IL
  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in September
Grant Park, IL

Average wind speed in September - Grant Park, IL
  • Average wind speed in September: 7.1mph

The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).

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Average humidity in September
Grant Park, IL

Average humidity in September - Grant Park, IL
  • Average humidity in September: 78%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).

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Average rainfall in September
Grant Park, IL

Average rainfall in September - Grant Park, IL
  • Average rainfall in September: 1.1"

The wettest month (with the highest rainfall) is May (2.2").
The driest month (with the least rainfall) is February (0.67").

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Average rainfall days in September
Grant Park, IL

Average rainfall days in September - Grant Park, IL
  • Average rainfall days in September: 11.6 days

The month with the highest number of rainy days is July (15.7 days).
The month with the least rainy days is February (5.1 days).

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Average snowfall in September
Grant Park, IL

Average snowfall in September - Grant Park, IL
  • Average snowfall in September: 0"

The month with the highest snowfall is January (1.42").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in September
Grant Park, IL

Average snowfall days in September - Grant Park, 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).

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Average daylight in September /
Average sunshine in September
Grant Park, IL

Average daylight in September / Average sunshine in September - Grant Park, 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 18min).

  • Average sunshine in September: 8h and 4min

The months with the most sunshine are June, July and August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

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Average sunshine days in September
Grant Park, IL

Average sunshine days in September - Grant Park, IL
  • Average sunshine days in September: 15.4 days

The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is July (10.7 days).

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Average UV index in September
Grant Park, IL

Average UV index in September - Grant Park, IL
  • Average UV index in September: 5

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).

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Average cloud cover in September
Grant Park, IL

Average cloud cover in September - Grant Park, IL
  • Average cloud cover in September: 33

The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 32).

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Average visibility in September
Grant Park, IL

Average visibility in September - Grant Park, 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).

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Grant Park, Illinois, USA

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