September weather forecast
Andover, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Andover, Illinois, with temperature in the range of an average low of 56.3°F (13.5°C) and an average high of 75.4°F (24.1°C).

Temperature

The transition into September notes an average high-temperature of a still moderately hot 75.4°F (24.1°C), revealing a mild distinction from the 80.2°F (26.8°C) in August. Andover experiences an average low-temperature of 56.3°F (13.5°C) in month of September.

Humidity

The average relative humidity in September is 76%.

Rainfall

In Andover, in September, during 9.9 rainfall days, 1.26" (32mm) of precipitation is typically accumulated. In Andover, during the entire year, the rain falls for 127.7 days and collects up to 17.8" (452mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:28 am and sunset at 7:33 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:44 pm CDT.

Sunshine

In September, the average sunshine is 9.4h.

UV index

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: A daily high UV index of 4 in September leads to these guidelines:
Be vigilant - Preventing sunburn is recommended. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Updated: Jul 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

During September, Andover experiences an average high-temperature of 75.4°F (24.1°C) and a low-temperature of 56.3°F (13.5°C). In July, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, is calculated to be 87.8°F (31°C).

What is the average humidity in September?

The average relative humidity in September in Andover is 76%.

How many days does it rain in September?

In September, the rain falls for 9.9 days. Throughout September, 1.26" (32mm) of precipitation is accumulated.

When it does not snow?

In Andover, snow does not fall in May through September.

Does it snow in September?

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

What is the average length of the day in September?

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

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:28 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 September, the average sunshine duration is 9.4h.

What is the UV index reading in September?

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium hazard to health from unprotected exposure to 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
Andover, IL

Average temperature in September - Andover, IL
  • Average high temperature in September: 75.4°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (28.2°F).

  • Average low temperature in September: 56.3°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 (16.5°F).

Average pressure in September
Andover, IL

Average pressure in September - Andover, IL
  • Average pressure in September: 30.02"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
Andover, IL

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

The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).

Average humidity in September
Andover, IL

Average humidity in September - Andover, 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
Andover, IL

Average rainfall in September - Andover, IL
  • Average rainfall in September: 1.26"

The wettest month (with the highest rainfall) is May (2.76").
The driest month (with the least rainfall) is December (0.71").

Average rainfall days in September
Andover, IL

Average rainfall days in September - Andover, IL
  • Average rainfall days in September: 9.9 days

The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is January (4 days).

Average snowfall in September
Andover, IL

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

The month with the highest snowfall is January (2.17").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Andover, IL

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

The month with the highest number of snowfall days is January (10.5 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
Andover, IL

Average daylight in September / Average sunshine in September - Andover, 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 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 0min).

Average sunshine days in September
Andover, IL

Average sunshine days in September - Andover, IL
  • Average sunshine days in September: 18 days

The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is July (11.2 days).

Average UV index in September
Andover, IL

Average UV index in September - Andover, 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 January (UV index 1).

Average cloud cover in September
Andover, IL

Average cloud cover in September - Andover, 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
Andover, IL

Average visibility in September - Andover, 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).

Andover, Illinois, USA

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