September weather forecast
Merrionette Park, IL

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Weather in September

September, the first month of the autumn in Merrionette Park, is still a warm month, with an average temperature varying between 73.6°F (23.1°C) and 59.2°F (15.1°C).

Temperature

The beginning of September brings a minor change in the average high-temperature, shifting from a warm 79.9°F (26.6°C) in August to a still moderately hot 73.6°F (23.1°C). Throughout September, Merrionette Park's nights cool down to an average of 59.2°F (15.1°C).

Humidity

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

Rainfall

In Merrionette Park, in September, it is raining for 13.5 days, with typically 1.97" (50mm) of accumulated precipitation. In Merrionette Park, during the entire year, the rain falls for 147.7 days and collects up to 23.62" (600mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

In Merrionette Park, the average length of the day in September is 12h and 28min.
On the first day of the month, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:33 pm CDT.

Sunshine

In Merrionette Park, the average sunshine in September is 9.1h.

UV index

The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: In September, the maximum UV index of 4 translates into these guidelines:
Ensure safety - Sun damage prevention is strongly urged. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
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Frequently asked questions

What are September temperatures in Merrionette Park?

The high-temperature, in September, in Merrionette Park, records 73.6°F (23.1°C), while the low-temperature is 59.2°F (15.1°C). The average heat index (a.k.a. 'real feel', 'feels like'), which combines relative humidity and air temperature, in July is appraised at 86°F (30°C).

What is the average humidity in September in Merrionette Park?

The average relative humidity in September is 75%.

How many days does it rain in September in Merrionette Park?

In Merrionette Park, during September, the rain falls for 13.5 days and regularly aggregates up to 1.97" (50mm) of precipitation.

When it does not snow in Merrionette Park?

May through September are months without snowfall in Merrionette Park.

Does it snow in Merrionette Park in September?

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

What is the average length of the day in September in Merrionette Park?

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

When is the sunrise / sunset in September in Merrionette Park?

On the first day of September, sunrise is at 6:17 am and sunset at 7:23 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 Merrionette Park have in September?

In September, the average sunshine duration in Merrionette Park is 9.1h.

How high is the UV index in September in Merrionette Park?

In Merrionette Park, Illinois, the average daily maximum UV index in September is 4. A UV Index value 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
Merrionette Park, IL

Average temperature in September - Merrionette Park, IL
  • Average high temperature in September: 73.6°F

The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (29.5°F).

  • Average low temperature in September: 59.2°F

The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

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Average pressure in September
Merrionette Park, IL

Average pressure in September - Merrionette Park, 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).

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Average wind speed in September
Merrionette Park, IL

Average wind speed in September - Merrionette Park, IL
  • Average wind speed in September: 7.7mph

The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).

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Average humidity in September
Merrionette Park, IL

Average humidity in September - Merrionette Park, 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%).

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Average rainfall in September
Merrionette Park, IL

Average rainfall in September - Merrionette Park, IL
  • Average rainfall in September: 1.97"

The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is December (1.02").

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Average rainfall days in September
Merrionette Park, IL

Average rainfall days in September - Merrionette Park, IL
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is July (18 days).
The month with the least rainy days is February (4.9 days).

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Average snowfall in September
Merrionette Park, IL

Average snowfall in September - Merrionette Park, IL
  • Average snowfall in September: 0"

The month with the highest snowfall is February (3.07").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
Merrionette Park, IL

Average snowfall days in September - Merrionette Park, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Merrionette Park, IL

Average daylight in September / Average sunshine in September - Merrionette Park, 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 1min

The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

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Average sunshine days in September
Merrionette Park, IL

Average sunshine days in September - Merrionette Park, IL
  • Average sunshine days in September: 13 days

The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is July (9.8 days).

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Average UV index in September
Merrionette Park, IL

Average UV index in September - Merrionette Park, 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).

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Average cloud cover in September
Merrionette Park, IL

Average cloud cover in September - Merrionette Park, IL
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 28).

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Average visibility in September
Merrionette Park, IL

Average visibility in September - Merrionette Park, 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).

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Merrionette Park, Illinois, USA

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