September weather forecast
Cortland, IL

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Weather in September

September, the first month of the autumn in Cortland, is also an agreeable month, with an average temperature varying between 73°F (22.8°C) and 54.5°F (12.5°C).

Temperature

The beginning of September brings a minor change in the average high-temperature, shifting from a moderately hot 78.4°F (25.8°C) in August to an agreeable 73°F (22.8°C). During September, Cortland experiences a consistent low-temperature average of 54.5°F (12.5°C).

Humidity

In September, the average relative humidity is 80%.

Rainfall

In Cortland, in September, during 12.2 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. Throughout the year, there are 152.6 rainfall days, and 32.09" (815mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall in Cortland.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:21 am and sunset at 7:27 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:37 pm CDT.

Sunshine

In September, the average sunshine is 8.5h.

UV index

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: In September, the UV index of 4 transforms into the following advice:
Exercise caution. Those with pale skin may experience burns in less than half an hour. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
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Frequently asked questions

What are the temperatures in Cortland in September?

Cortland in September has an average high-temperature of 73°F (22.8°C) and an average low-temperature of 54.5°F (12.5°C).

What is the average humidity in September in Cortland?

In September, the average relative humidity in Cortland is 80%.

How much does it rain in Cortland in September?

In Cortland, during September, the rain falls for 12.2 days and regularly aggregates up to 2.24" (57mm) of precipitation.

When it does not snow in Cortland?

In Cortland, snow does not fall in June through September.

Does it snow in Cortland in September?

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

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

The average day length in September in Cortland, Illinois, is 12h and 28min.

What time are sunrise and sunset in September in Cortland?

In September, on the first day of the month, sunrise is at 6:21 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:37 pm CDT.

How long on average sun shines in September in Cortland?

The average sunshine duration in September in Cortland, Illinois, is 8.5h.

How high is the UV index in September in Cortland?

In Cortland, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium hazard to health 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
Cortland, IL

Average temperature in September - Cortland, IL
  • Average high temperature in September: 73°F

The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (27°F).

  • Average low temperature in September: 54.5°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (15.1°F).

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Average pressure in September
Cortland, IL

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

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in September
Cortland, IL

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

The windiest month (with the highest average wind speed) is April (10mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).

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Average humidity in September
Cortland, IL

Average humidity in September - Cortland, IL
  • Average humidity in September: 80%

The months with the highest relative humidity are January and July (85%).
The months with the lowest relative humidity are April and October (75%).

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Average rainfall in September
Cortland, IL

Average rainfall in September - Cortland, IL
  • Average rainfall in September: 2.24"

The wettest month (with the highest rainfall) is May (4.37").
The driest month (with the least rainfall) is February (1.65").

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Average rainfall days in September
Cortland, IL

Average rainfall days in September - Cortland, IL
  • Average rainfall days in September: 12.2 days

The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (4.7 days).

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Average snowfall in September
Cortland, IL

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

The month with the highest snowfall is January (5.55").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in September
Cortland, IL

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

The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Cortland, IL

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

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in September: 8h and 3min

The month with the most sunshine is July (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).

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Average sunshine days in September
Cortland, IL

Average sunshine days in September - Cortland, IL
  • Average sunshine days in September: 15.7 days

The month with the most sunshine days is November (17.2 days).
The months with the least sunshine days are June and July (10.3 days).

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Average UV index in September
Cortland, IL

Average UV index in September - Cortland, IL
  • Average UV index in September: 4

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

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Average cloud cover in September
Cortland, IL

Average cloud cover in September - Cortland, IL
  • Average cloud cover in September: 35

The month with the most cloud cover is January (Cloud cover 63).
The months with the least cloud cover are August and September (Cloud cover 35).

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Average visibility in September
Cortland, IL

Average visibility in September - Cortland, IL
  • Average visibility in September: 5mi

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

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Cortland, Illinois, USA

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