September weather forecast
Saint Augustine, IL

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Saint Augustine, Illinois, with an average temperature ranging between max 76.1°F (24.5°C) and min 56.7°F (13.7°C).

Temperature

The unfolding of September shows an average high-temperature of a still warm 76.1°F (24.5°C), indicating a slight variance from August's 81.1°F (27.3°C). In September, the recorded average low-temperature is a refreshing 56.7°F (13.7°C).

Humidity

In Saint Augustine, the average relative humidity in September is 76%.

Rainfall

In September, the rain falls for 9.5 days. Throughout September, 1.22" (31mm) of precipitation is accumulated. In Saint Augustine, during the entire year, the rain falls for 126 days and collects up to 14.45" (367mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

In Saint Augustine, the average length of the day in September is 12h and 27min.
On the first day of September, sunrise is at 6:29 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:44 pm CDT.

Sunshine

The average sunshine in September is 9.3h.

UV index

In Saint Augustine, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Exercise care. People with light skin might get burns in fewer than 30 minutes. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Updated: Aug 22, 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 76.1°F (24.5°C) and a low-temperature of 56.7°F (13.7°C). In August, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is calculated to be 87.8°F (31°C).

What is the average humidity in September?

In September, the average relative humidity is 76%.

How much does it rain in September?

In September, the rain falls for 9.5 days. Throughout September, 1.22" (31mm) of precipitation is accumulated.

When it does not snow?

In Saint Augustine, Illinois, snow does not fall in May through September.

Does it snow in September?

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

What is the average length of the day in September?

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

What time are sunrise and sunset in September?

On the first day of September in Saint Augustine, Illinois, sunrise is at 6:29 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:44 pm CDT.

How long on average sun shines in September?

In Saint Augustine, the average sunshine duration in September is 9.3h.

How high is the UV index in September?

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 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
Saint Augustine, IL

Average temperature in September - Saint Augustine, IL
  • Average high temperature in September: 76.1°F

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (29.8°F).

  • Average low temperature in September: 56.7°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).

Average pressure in September
Saint Augustine, IL

Average pressure in September - Saint Augustine, IL
  • Average pressure in September: 30.02"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
Saint Augustine, IL

Average wind speed in September - Saint Augustine, IL
  • Average wind speed in September: 7.8mph

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).

Average humidity in September
Saint Augustine, IL

Average humidity in September - Saint Augustine, 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 (72%).

Average rainfall in September
Saint Augustine, IL

Average rainfall in September - Saint Augustine, IL
  • Average rainfall in September: 1.22"

The wettest month (with the highest rainfall) is May (2.2").
The driest months (with the least rainfall) are January and December (0.59").

Average rainfall days in September
Saint Augustine, IL

Average rainfall days in September - Saint Augustine, IL
  • Average rainfall days in September: 9.5 days

The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (4.4 days).

Average snowfall in September
Saint Augustine, IL

Average snowfall in September - Saint Augustine, IL
  • Average snowfall in September: 0"

The month with the highest snowfall is January (1.26").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Saint Augustine, IL

Average snowfall days in September - Saint Augustine, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (10.3 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
Saint Augustine, IL

Average daylight in September / Average sunshine in September - Saint Augustine, IL
  • Average daylight in September: 12h and 3min

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 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in September
Saint Augustine, IL

Average sunshine days in September - Saint Augustine, IL
  • Average sunshine days in September: 18.5 days

The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is July (11.2 days).

Average UV index in September
Saint Augustine, IL

Average UV index in September - Saint Augustine, 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, February, November and December (UV index 2).

Average cloud cover in September
Saint Augustine, IL

Average cloud cover in September - Saint Augustine, IL
  • Average cloud cover in September: 29

The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 29).

Average visibility in September
Saint Augustine, IL

Average visibility in September - Saint Augustine, IL
  • Average visibility in September: 6mi

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

Saint Augustine, Illinois, USA

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