September weather forecast
Quincy, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Quincy, Illinois, with an average temperature varying between 58.1°F (14.5°C) and 77.5°F (25.3°C).

Temperature

In September, the average high-temperature marginally decreases from 82.9°F (28.3°C) in August to a still moderately hot 77.5°F (25.3°C). Quincy's average low-temperature in September is measured at a mild 58.1°F (14.5°C).

Humidity

The average relative humidity in September is 75%.

Rainfall

In Quincy, during September, the rain falls for 10.4 days and regularly aggregates up to 2.4" (61mm) of precipitation. Throughout the year, there are 134.2 rainfall days, and 23.15" (588mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall.

Daylight

In September, the average length of the day is 12h and 26min.
On the first day of September, sunrise is at 6:34 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:49 pm CDT.

Sunshine

In September, the average sunshine in Quincy is 9.4h.

UV index

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. It's recommended to limit sun exposure when its radiation is at its peak during midday. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Quincy in September?

In September, in Quincy, the average high-temperature is 77.5°F (25.3°C), and the average low-temperature is 58.1°F (14.5°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines air temperature and relative humidity, in August is estimated at 91.4°F (33°C).

What is the average humidity in September in Quincy?

In Quincy, the average relative humidity in September is 75%.

How many days does it rain in September in Quincy?

In Quincy, in September, it is raining for 10.4 days, with typically 2.4" (61mm) of accumulated precipitation.

When it does not snow in Quincy?

May through September are months without snowfall in Quincy, Illinois.

Does it snow in Quincy in September?

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

What is the average length of the day in September in Quincy?

In Quincy, the average day length in September is 12h and 26min.

What time are sunrise and sunset in September in Quincy?

On the first day of September in Quincy, Illinois, sunrise is at 6:34 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:49 pm CDT.

How long on average sun shines in September in Quincy?

In Quincy, the average sunshine duration in September is 9.4h.

What is the UV index intensity in September in Quincy?

The average daily maximum UV index in September in Quincy is 5. A UV Index estimate of 3 to 5 represents a moderate vulnerability 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
Quincy, IL

Average temperature in September - Quincy, IL
  • Average high temperature in September: 77.5°F

The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (32.7°F).

  • Average low temperature in September: 58.1°F

The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).

Average pressure in September
Quincy, IL

Average pressure in September - Quincy, IL
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in September
Quincy, IL

Average wind speed in September - Quincy, IL
  • Average wind speed in September: 7.2mph

The windiest months (with the highest average wind speed) are January and February (10.3mph).
The calmest month (with the lowest average wind speed) is July (6.4mph).

Average humidity in September
Quincy, IL

Average humidity in September - Quincy, IL
  • Average humidity in September: 75%

The months with the highest relative humidity are June and July (81%).
The month with the lowest relative humidity is October (71%).

Average rainfall in September
Quincy, IL

Average rainfall in September - Quincy, IL
  • Average rainfall in September: 2.4"

The wettest month (with the highest rainfall) is May (3.35").
The driest months (with the least rainfall) are January and December (1.02").

Average rainfall days in September
Quincy, IL

Average rainfall days in September - Quincy, IL
  • Average rainfall days in September: 10.4 days

The month with the highest number of rainy days is May (16.9 days).
The month with the least rainy days is January (5 days).

Average snowfall in September
Quincy, IL

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

The month with the highest snowfall is January (2.76").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Quincy, IL

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

The month with the highest number of snowfall days is January (8.8 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
Quincy, IL

Average daylight in September / Average sunshine in September - Quincy, 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 24min).

  • Average sunshine in September: 9h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).

Average sunshine days in September
Quincy, IL

Average sunshine days in September - Quincy, IL
  • Average sunshine days in September: 18.1 days

The month with the most sunshine days is December (19.6 days).
The month with the least sunshine days is June (11.1 days).

Average UV index in September
Quincy, IL

Average UV index in September - Quincy, 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
Quincy, IL

Average cloud cover in September - Quincy, IL
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 53).
The month with the least cloud cover is July (Cloud cover 28).

Average visibility in September
Quincy, IL

Average visibility in September - Quincy, IL
  • Average visibility in September: 6mi

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

Quincy, Illinois, USA

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