September weather forecastStrawn, IL

September

Weather in September

The first month of the autumn, September, is still a warm month in Strawn, Illinois, with an average temperature fluctuating between 57.2°F (14°C) and 75.7°F (24.3°C).

Temperature

The advent of September signifies a minor shift to an average high-temperature of a still warm 75.7°F (24.3°C), aligning closely with August. Throughout September, Strawn encounters an average temperature drop to a mild 57.2°F (14°C).

Humidity

In September, the average relative humidity is 76%.

Rainfall

In Strawn, in September, during 10.5 rainfall days, 1.18" (30mm) of precipitation is typically accumulated. Throughout the year, there are 130.5 rainfall days, and 17.44" (443mm) of precipitation is accumulated.

Snowfall

In Strawn, snow does not fall in May through September.

Daylight

The average length of the day in September is 12h and 27min.
On the first day of September, sunrise is at 6:21 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:36 pm CDT.

Sunshine

The average sunshine in September in Strawn is 8.9h.

UV index

The average daily maximum UV index in September in Strawn is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for average individuals.
Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Exercise prevention - Protecting skin and eyes from harm is required. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Updated: Jun 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

The average high-temperature, in September, in Strawn, is 75.7°F (24.3°C), while the average low-temperature is 57.2°F (14°C). In July, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is computed to be 87.8°F (31°C).

In September, the average relative humidity is 76%.

In Strawn, during September, the rain falls for 10.5 days and regularly aggregates up to 1.18" (30mm) of precipitation.

May through September are months without snowfall.

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

The average day length in September is 12h and 27min.

On the first day of September, sunrise is at 6:21 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:36 pm CDT.

The average sunshine duration in September is 8.9h.

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 the Sun's UV radiation.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Strawn, IL

  • Average high temperature in September: 75.7°F

The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (30.6°F).

  • Average low temperature in September: 57.2°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).

Average pressure in September
Strawn, IL

  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in September
Strawn, IL

  • Average wind speed in September: 7.6mph

The windiest month (with the highest average wind speed) is January (10.8mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity in September
Strawn, IL

  • Average humidity in September: 76%

The month with the highest relative humidity is July (86%).
The month with the lowest relative humidity is October (71%).

Average rainfall in September
Strawn, IL

  • Average rainfall in September: 1.18"

The wettest month (with the highest rainfall) is May (2.56").
The driest month (with the least rainfall) is January (0.79").

Average rainfall days in September
Strawn, IL

  • Average rainfall days in September: 10.5 days

The month with the highest number of rainy days is May (17 days).
The months with the least rainy days are January and February (5 days).

Average snowfall in September
Strawn, IL

  • Average snowfall in September: 0"

The month with the highest snowfall is January (2.09").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Strawn, IL

  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (10.6 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
Strawn, IL

  • Average daylight in September: 12h and 24min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in September: 8h and 54min

The month with the most sunshine is June (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days in September
Strawn, IL

  • Average sunshine days in September: 17.2 days

The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (11.4 days).

Average UV index in September
Strawn, IL

  • Average UV index in September: 4

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

Average cloud cover in September
Strawn, IL

  • Average cloud cover in September: 32

The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is September (Cloud cover 32).

Average visibility in September
Strawn, 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).