September weather forecast
Spring Valley, IL

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Weather in September

September, the first month of the autumn in Spring Valley, is also a moderately hot month, with temperature in the range of an average low of 56.1°F (13.4°C) and an average high of 74.7°F (23.7°C).

Temperature

The arrival of September brings an average high-temperature of a still warm 74.7°F (23.7°C), nearly identical to August's 79.7°F (26.5°C). Spring Valley, in September, experiences an average temperature of 56.1°F (13.4°C) at night.

Humidity

In September, the average relative humidity is 78%.

Rainfall

In Spring Valley, in September, it is raining for 11.6 days, with typically 2.2" (56mm) of accumulated precipitation. In Spring Valley, Illinois, during the entire year, the rain falls for 152.7 days and collects up to 30.79" (782mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

In Spring Valley, 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

The average sunshine in September is 9h.

UV index

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the average person.
Note: A maximum high daily UV index of 4 during September translates into the following directions:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Updated: Aug 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

September temperatures vary between a high-temperature of 74.7°F (23.7°C) and a low-temperature of 56.1°F (13.4°C). In July, the average heat index (a.k.a. 'feels like', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is estimated at 86°F (30°C).

What is the average humidity in September?

In September, the average relative humidity is 78%.

How many days does it rain in September?

In September, the rain falls for 11.6 days. Throughout September, 2.2" (56mm) of precipitation is accumulated.

When it does not snow?

In Spring Valley, snow does not fall in May through September.

Does it snow in September?

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

What is the average length of the day in September?

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

What time are sunrise and sunset in September?

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 many hours of sunshine does Spring Valley have in September?

In Spring Valley, the average sunshine duration in September is 9h.

What is the UV index intensity in September?

The average daily maximum UV index in September in Spring Valley is 4. A UV Index of 3 to 5 symbolizes a medium health risk 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
Spring Valley, IL

Average temperature in September - Spring Valley, IL
  • Average high temperature in September: 74.7°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 (28.9°F).

  • Average low temperature in September: 56.1°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 (16.9°F).

Average pressure in September
Spring Valley, IL

Average pressure in September - Spring Valley, 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 (29.91"Hg).

Average wind speed in September
Spring Valley, IL

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

The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).

Average humidity in September
Spring Valley, IL

Average humidity in September - Spring Valley, IL
  • Average humidity in September: 78%

The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).

Average rainfall in September
Spring Valley, IL

Average rainfall in September - Spring Valley, IL
  • Average rainfall in September: 2.2"

The wettest month (with the highest rainfall) is May (4.69").
The driest months (with the least rainfall) are January and December (1.61").

Average rainfall days in September
Spring Valley, IL

Average rainfall days in September - Spring Valley, IL
  • Average rainfall days in September: 11.6 days

The month with the highest number of rainy days is May (18.9 days).
The month with the least rainy days is January (5.9 days).

Average snowfall in September
Spring Valley, IL

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

The month with the highest snowfall is January (4.09").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Spring Valley, IL

Average snowfall days in September - Spring Valley, IL
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is January (11.9 days).
The months with the least snowfall days are May, June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Spring Valley, IL

Average daylight in September / Average sunshine in September - Spring Valley, 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 18min).

  • Average sunshine in September: 9h and 0min

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

Average sunshine days in September
Spring Valley, IL

Average sunshine days in September - Spring Valley, IL
  • Average sunshine days in September: 16.1 days

The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is April (10.2 days).

Average UV index in September
Spring Valley, IL

Average UV index in September - Spring Valley, IL
  • Average UV index in September: 4

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

Average cloud cover in September
Spring Valley, IL

Average cloud cover in September - Spring Valley, IL
  • Average cloud cover in September: 32

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

Average visibility in September
Spring Valley, IL

Average visibility in September - Spring Valley, IL
  • Average visibility in September: 6mi

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

Spring Valley, Illinois, USA

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