September weather forecastWest Chicago, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in West Chicago, Illinois, with an average temperature ranging between max 73.4°F (23°C) and min 56.5°F (13.6°C).Temperature
During the shift to September, West Chicago records a mild decrease in average high-temperature, moving from a moderately hot 79.5°F (26.4°C) in August to a still warm 73.4°F (23°C). During September, the temperature is averaged to a low of 56.5°F (13.6°C) at night.Humidity
In September, the average relative humidity is 78%.Rainfall
In West Chicago, in September, it is raining for 9.5 days, with typically 0.71" (18mm) of accumulated precipitation. In West Chicago, during the entire year, the rain falls for 101.9 days and collects up to 8.58" (218mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:19 am and sunset at 7:25 pm. On the last day of September, sunrise is at 6:49 am and sunset at 6:35 pm CDT.
Sunshine
In September, the average sunshine in West Chicago is 8.8h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: The average daily UV index of 4 in September transforms into the following instructions:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
West Chicago, IL
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (27.9°F).
- Average low temperature in September: 56.5°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 (16.2°F).
Average pressure in September
West Chicago, 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
West Chicago, IL
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in September
West Chicago, IL
- Average humidity in September: 78%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
West Chicago, IL
- Average rainfall in September: 0.71"
The wettest month (with the highest rainfall) is May (1.26").
The driest months (with the least rainfall) are November and December (0.39").
Average rainfall days in September
West Chicago, IL
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is May (12.4 days).
The month with the least rainy days is January (3.4 days).
Average snowfall in September
West Chicago, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.14").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
West Chicago, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
West Chicago, IL
- Average daylight in September: 12h and 30min
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 48min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
West Chicago, IL
- Average sunshine days in September: 17.7 days
The month with the most sunshine days is December (22.4 days).
The month with the least sunshine days is June (13.3 days).
Average UV index in September
West Chicago, IL
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
West Chicago, 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 September (Cloud cover 32).
Average visibility in September
West Chicago, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
