September weather forecast
Wilsonville, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Wilsonville, Illinois, with an average temperature ranging between min 59.4°F (15.2°C) and max 77.9°F (25.5°C).

Temperature

The shift into September uncovers an average high-temperature of a still moderately hot 77.9°F (25.5°C), subtly different from the previous month. Throughout September, the nighttime temperature averages to a refreshing 59.4°F (15.2°C).

Humidity

The average relative humidity in September is 75%.

Rainfall

In Wilsonville, Illinois, in September, it is raining for 10.4 days, with typically 0.83" (21mm) of accumulated precipitation. Throughout the year, in Wilsonville, there are 121.4 rainfall days, and 14.72" (374mm) of precipitation is accumulated.

Snowfall

In Wilsonville, snow does not fall in April through October.

Daylight

The average length of the day in September in Wilsonville is 12h and 26min.
On the first day of the month, sunrise is at 6:28 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:43 pm CDT.

Sunshine

In Wilsonville, the average sunshine in September is 9.3h.

UV index

In Wilsonville, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, the maximum UV index of 5 suggests these recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Wilsonville in September?

The average high-temperature, in September, in Wilsonville, is 77.9°F (25.5°C), while the average low-temperature is 59.4°F (15.2°C). In August, the average heat index (a.k.a. 'real feel', 'feels like'), which factors the actual air temperature with the relative humidity, is calculated to be 91.4°F (33°C).

What is the average humidity in September in Wilsonville?

The average relative humidity in September in Wilsonville, Illinois, is 75%.

How many days does it rain in September in Wilsonville?

In September, in Wilsonville, Illinois, the rain falls for 10.4 days. Throughout September, 0.83" (21mm) of precipitation is accumulated.

When it does not snow in Wilsonville?

In Wilsonville, Illinois, snow does not fall in April through October.

How many hours of daylight does Wilsonville have in September?

In September, the average day length in Wilsonville is 12h and 26min.

When is the sunrise / sunset in September in Wilsonville?

In September, on the first day of the month, sunrise is at 6:28 am and sunset at 7:29 pm. On the last day of the month, in Wilsonville, sunrise is at 6:55 am and sunset at 6:43 pm CDT.

How long on average sun shines in September in Wilsonville?

The average sunshine duration in September in Wilsonville is 9.3h.

How high is the UV index in September in Wilsonville?

In Wilsonville, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate vulnerability from 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
Wilsonville, IL

Average temperature in September - Wilsonville, IL
  • Average high temperature in September: 77.9°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.6°F).

  • Average low temperature in September: 59.4°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).

Average pressure in September
Wilsonville, IL

Average pressure in September - Wilsonville, IL
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in September
Wilsonville, IL

Average wind speed in September - Wilsonville, IL
  • Average wind speed in September: 6.4mph

The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).

Average humidity in September
Wilsonville, IL

Average humidity in September - Wilsonville, IL
  • Average humidity in September: 75%

The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).

Average rainfall in September
Wilsonville, IL

Average rainfall in September - Wilsonville, IL
  • Average rainfall in September: 0.83"

The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is February (0.67").

Average rainfall days in September
Wilsonville, IL

Average rainfall days in September - Wilsonville, IL
  • Average rainfall days in September: 10.4 days

The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is January (5.8 days).

Average snowfall in September
Wilsonville, IL

Average snowfall in September - Wilsonville, IL
  • Average snowfall in September: 0"

The month with the highest snowfall is December (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in September
Wilsonville, IL

Average snowfall days in September - Wilsonville, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.3 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
Wilsonville, IL

Average daylight in September / Average sunshine in September - Wilsonville, IL
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in September: 9h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

Average sunshine days in September
Wilsonville, IL

Average sunshine days in September - Wilsonville, IL
  • Average sunshine days in September: 17.2 days

The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is July (12.5 days).

Average UV index in September
Wilsonville, IL

Average UV index in September - Wilsonville, IL
  • Average UV index in September: 5

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
Wilsonville, IL

Average cloud cover in September - Wilsonville, IL
  • Average cloud cover in September: 29

The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).

Average visibility in September
Wilsonville, IL

Average visibility in September - Wilsonville, 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).

Wilsonville, Illinois, USA

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