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
September's commencement is accompanied by an average high-temperature of a still warm 74.8°F (23.8°C), diverging marginally from August's 79.7°F (26.5°C). In Grant Park, an average temperature of 56.8°F (13.8°C) is noted during September nights.Humidity
The average relative humidity in September is 78%.Rainfall
In Grant Park, during September, the rain falls for 11.6 days and regularly aggregates up to 1.1" (28mm) of precipitation. In Grant Park, during the entire year, the rain falls for 132 days and collects up to 15.16" (385mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September in Grant Park is 12h and 28min.On the first day of September, 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 September, the average sunshine is 8.7h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for average individuals.Note: The daily high UV index of 5 during September translates into the following recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. To guard against the harmful effects of the Sun, minimize exposure during midday. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Grant Park have in September?
What is the UV index intensity in September?
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).
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).
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).
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%).
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").
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).
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").
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).
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).
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).
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).
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).
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).
Grant Park, Illinois, USA
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