September weather forecast
Green Valley, IL

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Weather in September

September, the first month of the autumn in Green Valley, is also a moderately hot month, with an average temperature varying between 76.5°F (24.7°C) and 57.9°F (14.4°C).

Temperature

September begins with an average high-temperature of a still moderately hot 76.5°F (24.7°C), reflecting close similarity to the preceding month. During September, Green Valley records a consistent average nighttime temperature of 57.9°F (14.4°C).

Humidity

The average relative humidity in September is 76%.

Rainfall

In September, the rain falls for 10.3 days. Throughout September, 1.57" (40mm) of precipitation is accumulated. In Green Valley, during the entire year, the rain falls for 131.4 days and collects up to 20.08" (510mm) of precipitation.

Snowfall

In Green Valley, snow does not fall in May through October.

Daylight

In Green Valley, the average length of the day in September is 12h and 27min.
On the first day of September in Green Valley, sunrise is at 6:26 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:41 pm CDT.

Sunshine

The average sunshine in September is 9.1h.

UV index

In Green Valley, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for average individuals.
Note: In September, the maximum UV index of 5 suggests these recommendations:
Exercise prevention - Protecting skin and eyes from harm is required. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Updated: Aug 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

Green Valley in September has an average high-temperature of 76.5°F (24.7°C) and an average low-temperature of 57.9°F (14.4°C). In August, the average heat index (a.k.a. 'real feel', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, is appraised at 87.8°F (31°C).

What is the average humidity in September?

The average relative humidity in September is 76%.

How many days does it rain in September?

In Green Valley, in September, it is raining for 10.3 days, with typically 1.57" (40mm) of accumulated precipitation.

When it does not snow?

In Green Valley, snow does not fall in May through October.

How many hours of daylight does Green Valley have in September?

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

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:26 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:41 pm CDT.

How many hours of sunshine does Green Valley have in September?

In Green Valley, the average sunshine duration in September is 9.1h.

What is the UV index intensity in September?

The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate health threat 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
Green Valley, IL

Average temperature in September - Green Valley, IL
  • Average high temperature in September: 76.5°F

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (31.5°F).

  • Average low temperature in September: 57.9°F

The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).

Average pressure in September
Green Valley, IL

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

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in September
Green Valley, IL

Average wind speed in September - Green Valley, IL
  • Average wind speed in September: 7.5mph

The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity in September
Green Valley, IL

Average humidity in September - Green Valley, IL
  • Average humidity in September: 76%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (71%).

Average rainfall in September
Green Valley, IL

Average rainfall in September - Green Valley, IL
  • Average rainfall in September: 1.57"

The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is February (1.02").

Average rainfall days in September
Green Valley, IL

Average rainfall days in September - Green Valley, IL
  • Average rainfall days in September: 10.3 days

The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (5.1 days).

Average snowfall in September
Green Valley, IL

Average snowfall in September - Green Valley, IL
  • Average snowfall in September: 0"

The month with the highest snowfall is January (2.87").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Green Valley, IL

Average snowfall days in September - Green Valley, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (8.4 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
Green Valley, IL

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

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: 9h and 1min

The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).

Average sunshine days in September
Green Valley, IL

Average sunshine days in September - Green Valley, IL
  • Average sunshine days in September: 18.8 days

The month with the most sunshine days is November (20 days).
The month with the least sunshine days is May (11.8 days).

Average UV index in September
Green Valley, IL

Average UV index in September - Green Valley, IL
  • Average UV index in September: 5

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

Average cloud cover in September
Green Valley, IL

Average cloud cover in September - Green Valley, IL
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 30).

Average visibility in September
Green Valley, IL

Average visibility in September - Green Valley, 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).

Green Valley, Illinois, USA

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