September weather forecast
Wilmette, IL

Share

Weather in September

September, the first month of the autumn in Wilmette, is also an agreeable month, with an average temperature fluctuating between 70.7°F (21.5°C) and 61.7°F (16.5°C).

Temperature

A modest decline in the average high-temperature is seen during September, decreasing from a moderately hot 77°F (25°C) in August to an agreeable 70.7°F (21.5°C). The month of September in Wilmette is marked by an average minimum temperature of 61.7°F (16.5°C), slightly cooler than its daytime counterpart.

Humidity

In Wilmette, the average relative humidity in September is 75%.

Rainfall

In Wilmette, Illinois, in September, it is raining for 14.9 days, with typically 3.11" (79mm) of accumulated precipitation. In Wilmette, during the entire year, the rain falls for 154.1 days and collects up to 33.31" (846mm) of precipitation.

Snowfall

May through September are months without snowfall in Wilmette.

Daylight

In September, the average length of the day in Wilmette is 12h and 28min.
On the first day of the month, sunrise is at 6:17 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:33 pm CDT.

Sunshine

In September, the average sunshine is 9h.

UV index

The average daily maximum UV index in September in Wilmette is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the average person.
Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Boost your sun resistance with garments that are densely woven yet spacious.
[Resources]

Frequently asked questions

What is the usual temperature for Wilmette in September?

The high-temperature, in September, in Wilmette, is 70.7°F (21.5°C), while the low-temperature averages to 61.7°F (16.5°C).

What is the average humidity in September in Wilmette?

The average relative humidity in September in Wilmette is 75%.

How many days does it rain in September in Wilmette?

In Wilmette, in September, during 14.9 rainfall days, 3.11" (79mm) of precipitation is typically accumulated.

When it does not snow in Wilmette?

May through September are months without snowfall in Wilmette, Illinois.

Does it snow in Wilmette in September?

In Wilmette, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September in Wilmette?

The average day length in September is 12h and 28min.

What time are sunrise and sunset in September in Wilmette?

On the first day of September, sunrise is at 6:17 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:33 pm CDT.

How many hours of sunshine does Wilmette have in September?

In Wilmette, the average sunshine duration in September is 9h.

What is the UV index intensity in September in Wilmette?

In Wilmette, Illinois, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability 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
Wilmette, IL

Average temperature in September - Wilmette, IL
  • Average high temperature in September: 70.7°F

The warmest month (with the highest average high temperature) is August (77°F).
The month with the lowest average high temperature is January (29.1°F).

  • Average low temperature in September: 61.7°F

The months with the highest average low temperature are July and August (68°F).
The coldest month (with the lowest average low temperature) is January (20.5°F).

[Resources]

Average pressure in September
Wilmette, IL

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

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

[Resources]

Average wind speed in September
Wilmette, IL

Average wind speed in September - Wilmette, IL
  • Average wind speed in September: 9.6mph

The windiest month (with the highest average wind speed) is January (12.7mph).
The calmest months (with the lowest average wind speed) are July and August (8mph).

[Resources]

Average humidity in September
Wilmette, IL

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

The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is October (73%).

[Resources]

Average rainfall in September
Wilmette, IL

Average rainfall in September - Wilmette, IL
  • Average rainfall in September: 3.11"

The wettest month (with the highest rainfall) is June (4.49").
The driest month (with the least rainfall) is December (1.38").

[Resources]

Average rainfall days in September
Wilmette, IL

Average rainfall days in September - Wilmette, IL
  • Average rainfall days in September: 14.9 days

The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is February (5.6 days).

[Resources]

Average snowfall in September
Wilmette, IL

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

The month with the highest snowfall is January (3.58").
The months with the least snowfall are May, June, July, August and September (0").

[Resources]

Average snowfall days in September
Wilmette, IL

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

The month with the highest number of snowfall days is January (11.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

[Resources]

Average daylight in September /
Average sunshine in September
Wilmette, IL

Average daylight in September / Average sunshine in September - Wilmette, 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: 9h and 0min

The months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).

[Resources]

Average sunshine days in September
Wilmette, IL

Average sunshine days in September - Wilmette, IL
  • Average sunshine days in September: 13 days

The month with the most sunshine days is December (15.3 days).
The months with the least sunshine days are June and July (10.9 days).

[Resources]

Average UV index in September
Wilmette, IL

Average UV index in September - Wilmette, 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 December (UV index 1).

[Resources]

Average cloud cover in September
Wilmette, IL

Average cloud cover in September - Wilmette, IL
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July and August (Cloud cover 27).

[Resources]

Average visibility in September
Wilmette, IL

Average visibility in September - Wilmette, 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).

[Resources]

Wilmette, Illinois, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location