September weather forecast
Mundelein, IL

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Weather in September

The first month of the autumn, September, is still a pleasant month in Mundelein, Illinois, with an average temperature fluctuating between 72.9°F (22.7°C) and 57.4°F (14.1°C).

Temperature

In September, the average high-temperature marginally decreases from a warm 79.3°F (26.3°C) in August to a pleasant 72.9°F (22.7°C). The temperature in Mundelein lowers to an average of 57.4°F (14.1°C) during September nights.

Humidity

The average relative humidity in September in Mundelein is 76%.

Rainfall

In September, in Mundelein, the rain falls for 12.9 days. Throughout September, 2.05" (52mm) of precipitation is accumulated. Throughout the year, in Mundelein, there are 147.3 rainfall days, and 27.44" (697mm) of precipitation is accumulated.

Snowfall

June 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 6:18 am and sunset at 7:25 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:34 pm CDT.

Sunshine

The average sunshine in September in Mundelein is 9h.

UV index

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for average individuals.
Note: The maximum UV index of 4 during September translates into these guidelines:
Ensure safety - Imperative it is to shield skin and eyes from damage. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
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Frequently asked questions

What are September temperatures in Mundelein?

In Mundelein, 72.9°F (22.7°C) is the average high-temperature and 57.4°F (14.1°C) is the average low-temperature during September.

What is the average humidity in September in Mundelein?

In Mundelein, Illinois, the average relative humidity in September is 76%.

How much does it rain in Mundelein in September?

In Mundelein, Illinois, in September, during 12.9 rainfall days, 2.05" (52mm) of precipitation is typically accumulated.

When it does not snow in Mundelein?

In Mundelein, Illinois, snow does not fall in June through September.

Does it snow in Mundelein in September?

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

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

In September, the average day length in Mundelein is 12h and 28min.

When is the sunrise / sunset in September in Mundelein?

On the first day of September in Mundelein, sunrise is at 6:18 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:34 pm CDT.

How long on average sun shines in September in Mundelein?

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

How high is the UV index in September in Mundelein?

In Mundelein, Illinois, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health threat from unsafe 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
Mundelein, IL

Average temperature in September - Mundelein, IL
  • Average high temperature in September: 72.9°F

The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is January (27.9°F).

  • Average low temperature in September: 57.4°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).

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Average pressure in September
Mundelein, IL

Average pressure in September - Mundelein, 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).

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Average wind speed in September
Mundelein, IL

Average wind speed in September - Mundelein, IL
  • Average wind speed in September: 7.5mph

The windiest month (with the highest average wind speed) is January (10.3mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

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Average humidity in September
Mundelein, IL

Average humidity in September - Mundelein, IL
  • Average humidity in September: 76%

The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).

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Average rainfall in September
Mundelein, IL

Average rainfall in September - Mundelein, IL
  • Average rainfall in September: 2.05"

The wettest month (with the highest rainfall) is June (3.54").
The driest months (with the least rainfall) are November and December (1.3").

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Average rainfall days in September
Mundelein, IL

Average rainfall days in September - Mundelein, IL
  • Average rainfall days in September: 12.9 days

The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is February (4.3 days).

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Average snowfall in September
Mundelein, IL

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

The month with the highest snowfall is February (5.55").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in September
Mundelein, IL

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

The month with the highest number of snowfall days is January (12.9 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Mundelein, 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 6min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

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Average sunshine days in September
Mundelein, IL

Average sunshine days in September - Mundelein, IL
  • Average sunshine days in September: 14.5 days

The month with the most sunshine days is November (16.6 days).
The month with the least sunshine days is June (10 days).

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Average UV index in September
Mundelein, IL

Average UV index in September - Mundelein, IL
  • Average UV index in September: 4

The months with the highest UV index are July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

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Average cloud cover in September
Mundelein, IL

Average cloud cover in September - Mundelein, IL
  • Average cloud cover in September: 31

The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 30).

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Average visibility in September
Mundelein, IL

Average visibility in September - Mundelein, IL
  • Average visibility in September: 6mi

The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).

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Mundelein, Illinois, USA

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