September weather forecast
Richton Park, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Richton Park, Illinois, with temperature in the range of an average low of 58.3°F (14.6°C) and an average high of 73.9°F (23.3°C).

Temperature

September's arrival coincides with a soft drop in the average high-temperature, subtly decreasing from August's 80.1°F (26.7°C) to a still moderately hot 73.9°F (23.3°C). During the month of September, the temperature generally drops to a low average of 58.3°F (14.6°C).

Humidity

In September, the average relative humidity in Richton Park is 76%.

Rainfall

In Richton Park, during September, the rain falls for 13.4 days and regularly aggregates up to 2.48" (63mm) of precipitation. Throughout the year, in Richton Park, Illinois, there are 155.6 rainfall days, and 31.3" (795mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall in Richton Park.

Daylight

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

Sunshine

In September, the average sunshine is 8.8h.

UV index

In Richton Park, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.
Note: A daily high UV index of 4 in September leads to these guidelines:
Be vigilant - Preventing sunburn is recommended. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures in Richton Park?

In September, in Richton Park, the average high-temperature is 73.9°F (23.3°C), and the average low-temperature is 58.3°F (14.6°C). In July, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which factors the actual air temperature with the relative humidity, is estimated at 87.8°F (31°C).

What is the average humidity in September in Richton Park?

In Richton Park, the average relative humidity in September is 76%.

How much does it rain in Richton Park in September?

In September, the rain falls for 13.4 days. Throughout September, 2.48" (63mm) of precipitation is accumulated.

When it does not snow in Richton Park?

May through September are months without snowfall.

Does it snow in Richton Park in September?

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

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

The average day length in September in Richton Park is 12h and 28min.

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

In September, on the first day of the month, 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 long on average sun shines in September in Richton Park?

In Richton Park, Illinois, the average sunshine duration in September is 8.8h.

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

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate vulnerability 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
Richton Park, IL

Average temperature in September - Richton Park, IL
  • Average high temperature in September: 73.9°F

The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.7°F).

  • Average low temperature in September: 58.3°F

The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

Average pressure in September
Richton Park, IL

Average pressure in September - Richton 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).

Average wind speed in September
Richton Park, IL

Average wind speed in September - Richton Park, IL
  • Average wind speed in September: 7.3mph

The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).

Average humidity in September
Richton Park, IL

Average humidity in September - Richton Park, IL
  • Average humidity in September: 76%

The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).

Average rainfall in September
Richton Park, IL

Average rainfall in September - Richton Park, IL
  • Average rainfall in September: 2.48"

The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is December (1.54").

Average rainfall days in September
Richton Park, IL

Average rainfall days in September - Richton Park, IL
  • Average rainfall days in September: 13.4 days

The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (6.1 days).

Average snowfall in September
Richton Park, IL

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

The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Richton Park, IL

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

The month with the highest number of snowfall days is January (12.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Richton Park, 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 5min

The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).

Average sunshine days in September
Richton Park, IL

Average sunshine days in September - Richton Park, IL
  • Average sunshine days in September: 14 days

The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.2 days).

Average UV index in September
Richton Park, IL

Average UV index in September - Richton Park, 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
Richton Park, IL

Average cloud cover in September - Richton Park, IL
  • Average cloud cover in September: 32

The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in September
Richton Park, IL

Average visibility in September - Richton Park, IL
  • Average visibility in September: 6mi

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

Richton Park, Illinois, USA

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