September weather forecast
Perks, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Perks, Illinois, with an average temperature varying between 60.6°F (15.9°C) and 81.1°F (27.3°C).

Temperature

Perks's weather subtly changes with the onset of September, barely falling from a hot 86.5°F (30.3°C) in August to a moderately hot 81.1°F (27.3°C). Throughout September, an average low-temperature of 60.6°F (15.9°C) is expected.

Heat index

The heat index in September is calculated to be a hot 86°F (30°C). Ongoing exposure and activity could lead to a state of exhaustion, with a chance of heat cramps.
When considering the heat index, it's pivotal to note it is for shade and mild wind conditions. Facing direct sunlight may hike up the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', gives an indication of how one might feel in terms of heat after considering humidity. This effect is subjective, differing among individuals based on their physical activity and perception of heat, which can be influenced by factors like wind, clothing, and metabolic variances. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.

Humidity

The average relative humidity in September is 73%.

Rainfall

The month with the least rainfall is September, when the rain falls for 8.3 days and typically collects 0.47" (12mm) of precipitation.

Snowfall

In Perks, Illinois, snow does not fall in April through October.

Daylight

In Perks, the average length of the day in September is 12h and 25min.
On the first day of the month, sunrise is at 6:27 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:40 pm CDT.

Sunshine

The average sunshine in September is 9.4h.

UV index

The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.
Note: A maximum daily UV index of 5 during September morphs into the following directions:
Put precautions into practice - Ensuring skin and eye safety is a necessity. To avoid the Sun's strongest rays, limit exposure around the mid-day period. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Updated: Jul 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

In Perks, in September, the average high-temperature is 81.1°F (27.3°C), and the average low-temperature is 60.6°F (15.9°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), which represents the influence of relative humidity on air temperature, in September is calculated to be 86°F (30°C).

What is the average humidity in September?

In Perks, the average relative humidity in September is 73%.

What is the driest month?

September is the month with the least rainfall. Rain falls for 8.3 days and accumulates 0.47" (12mm) of precipitation.

How many days does it rain in September?

In September, the rain falls for 8.3 days. Throughout September, 0.47" (12mm) of precipitation is accumulated.

When it does not snow?

In Perks, snow does not fall in April through October.

How many hours of daylight does Perks have in September?

The average day length in September is 12h and 25min.

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:27 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:40 pm CDT.

How long on average sun shines in September in Perks?

In Perks, the average sunshine duration in September is 9.4h.

What is the UV index intensity in September?

The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents 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
Perks, IL

Average temperature in September - Perks, IL
  • Average high temperature in September: 81.1°F

The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (40.1°F).

  • Average low temperature in September: 60.6°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (27°F).

Average pressure in September
Perks, IL

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

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in September
Perks, IL

Average wind speed in September - Perks, IL
  • Average wind speed in September: 6.3mph

The windiest months (with the highest average wind speed) are January and February (9mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).

Average humidity in September
Perks, IL

Average humidity in September - Perks, IL
  • Average humidity in September: 73%

The months with the highest relative humidity are March and May (79%).
The month with the lowest relative humidity is October (71%).

Average rainfall in September
Perks, IL

Average rainfall in September - Perks, IL
  • Average rainfall in September: 0.47"

The wettest month (with the highest rainfall) is June (1.5").
The driest month (with the least rainfall) is September (0.47").

Average rainfall days in September
Perks, IL

Average rainfall days in September - Perks, IL
  • Average rainfall days in September: 8.3 days

The month with the highest number of rainy days is July (13.1 days).
The months with the least rainy days are January, February and December (7.3 days).

Average snowfall in September
Perks, IL

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

The month with the highest snowfall is February (0.67").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in September
Perks, IL

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

The month with the highest number of snowfall days is January (3.3 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
Perks, IL

Average daylight in September / Average sunshine in September - Perks, IL
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in September: 9h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 4h and 36min).

Average sunshine days in September
Perks, IL

Average sunshine days in September - Perks, IL
  • Average sunshine days in September: 19.1 days

The month with the most sunshine days is October (21.5 days).
The month with the least sunshine days is June (14.8 days).

Average UV index in September
Perks, IL

Average UV index in September - Perks, IL
  • Average UV index in September: 5

The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).

Average cloud cover in September
Perks, IL

Average cloud cover in September - Perks, IL
  • Average cloud cover in September: 28

The months with the most cloud cover are January and February (Cloud cover 51).
The month with the least cloud cover is September (Cloud cover 28).

Average visibility in September
Perks, IL

Average visibility in September - Perks, 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).

Perks, Illinois, USA

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