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 beginning of September in Downers Grove, Illinois, brings a slight decrease in the average high-temperature, transitioning from 81.1°F (27.3°C) in August to a still moderately hot 74.3°F (23.5°C). Throughout the nights in September, Downers Grove experiences an average low-temperature of 57.9°F (14.4°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In Downers Grove, during September, the rain falls for 11.5 days and regularly aggregates up to 1.18" (30mm) of precipitation. In Downers Grove, during the entire year, the rain falls for 118.5 days and collects up to 13.74" (349mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In September, the average length of the day in Downers Grove is 12h and 28min.On the first day of September in Downers Grove, sunrise is at 6:18 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:34 pm CDT.
Sunshine
In September, the average sunshine in Downers Grove is 8.7h.UV index
The average daily maximum UV index in September in Downers Grove is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 4 suggests this advice:
Ensure safety - Recommendations to avert sunburn are presented. Minimize direct exposure to the Sun during midday when its radiation is at its peak. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Frequently asked questions
What are the temperatures in Downers Grove in September?
What is the average humidity in September in Downers Grove?
How many days does it rain in September in Downers Grove?
When it does not snow in Downers Grove?
Does it snow in Downers Grove in September?
How many hours of daylight does Downers Grove have in September?
When is the sunrise / sunset in September in Downers Grove?
How many hours of sunshine does Downers Grove have in September?
What is the UV index intensity in September in Downers Grove?
Average temperature in September
Downers Grove, IL
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in September: 57.9°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (17.1°F).
Average pressure in September
Downers Grove, 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
Downers Grove, IL
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is January (9.7mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in September
Downers Grove, IL
- Average humidity in September: 75%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Downers Grove, IL
- Average rainfall in September: 1.18"
The wettest month (with the highest rainfall) is May (1.97").
The driest month (with the least rainfall) is December (0.63").
Average rainfall days in September
Downers Grove, IL
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is May (14.9 days).
The month with the least rainy days is February (4.2 days).
Average snowfall in September
Downers Grove, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.28").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Downers Grove, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Downers Grove, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 4min
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
Downers Grove, IL
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is December (20.7 days).
The month with the least sunshine days is July (11.8 days).
Average UV index in September
Downers Grove, IL
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Downers Grove, 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 31).
Average visibility in September
Downers Grove, 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).
Downers Grove, Illinois, USA
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