September weather forecast
Arlington, IL

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Arlington, Illinois, with an average temperature fluctuating between 74.1°F (23.4°C) and 55.8°F (13.2°C).

Temperature

The transition into September is marked with an average high-temperature of a still moderately hot 74.1°F (23.4°C), showing an insignificant shift from August's 79.2°F (26.2°C). An average low-temperature of 55.8°F (13.2°C) is recorded in the month of September.

Humidity

In Arlington, the average relative humidity in September is 79%.

Rainfall

In Arlington, in September, it is raining for 8.5 days, with typically 0.71" (18mm) of accumulated precipitation. In Arlington, Illinois, during the entire year, the rain falls for 107.9 days and collects up to 9.96" (253mm) of precipitation.

Snowfall

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

Daylight

In Arlington, the average length of the day in September is 12h and 28min.
On the first day of the month, sunrise is at 6:23 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:53 am and sunset at 6:39 pm CDT.

Sunshine

In September, the average sunshine in Arlington is 8.6h.

UV index

In September, the average daily maximum UV index in Arlington, Illinois, is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: The maximum UV index, 4 during September, leads to the following recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.
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 Arlington in September?

The average high-temperature and low-temperature in Arlington during September are 74.1°F (23.4°C) and 55.8°F (13.2°C) respectively. The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which factors the actual air temperature with the relative humidity, in July is estimated at 86°F (30°C).

What is the average humidity in September in Arlington?

In September, the average relative humidity is 79%.

How many days does it rain in September in Arlington?

In September, in Arlington, Illinois, the rain falls for 8.5 days. Throughout September, 0.71" (18mm) of precipitation is accumulated.

When it does not snow in Arlington?

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

Does it snow in Arlington in September?

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

How many hours of daylight does Arlington have in September?

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

What time are sunrise and sunset in September in Arlington?

In September, on the first day of the month, sunrise is at 6:23 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 6:39 pm CDT.

How long on average sun shines in September in Arlington?

In Arlington, Illinois, the average sunshine duration in September is 8.6h.

How high is the UV index in September in Arlington?

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

Average temperature in September - Arlington, IL
  • Average high temperature in September: 74.1°F

The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (28.6°F).

  • Average low temperature in September: 55.8°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 (16.7°F).

Average pressure in September
Arlington, IL

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

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in September
Arlington, IL

Average wind speed in September - Arlington, IL
  • Average wind speed in September: 7.4mph

The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).

Average humidity in September
Arlington, IL

Average humidity in September - Arlington, IL
  • Average humidity in September: 79%

The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (73%).

Average rainfall in September
Arlington, IL

Average rainfall in September - Arlington, IL
  • Average rainfall in September: 0.71"

The wettest month (with the highest rainfall) is May (1.42").
The driest months (with the least rainfall) are January, February, November and December (0.51").

Average rainfall days in September
Arlington, IL

Average rainfall days in September - Arlington, IL
  • Average rainfall days in September: 8.5 days

The month with the highest number of rainy days is May (13.8 days).
The month with the least rainy days is January (3.6 days).

Average snowfall in September
Arlington, IL

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

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

Average snowfall days in September
Arlington, IL

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

The month with the highest number of snowfall days is January (8.6 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
Arlington, IL

Average daylight in September / Average sunshine in September - Arlington, IL
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in September: 8h and 4min

The months with the most sunshine are June, July and August (Average sunshine: 9h and 30min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in September
Arlington, IL

Average sunshine days in September - Arlington, IL
  • Average sunshine days in September: 19.4 days

The month with the most sunshine days is December (21.8 days).
The month with the least sunshine days is July (13.3 days).

Average UV index in September
Arlington, IL

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

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in September
Arlington, IL

Average cloud cover in September - Arlington, IL
  • Average cloud cover in September: 33

The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is September (Cloud cover 33).

Average visibility in September
Arlington, IL

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

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

Arlington, Illinois, USA

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