September weather forecast
Naples, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Naples, Illinois, with an average temperature varying between 78.1°F (25.6°C) and 58.8°F (14.9°C).

Temperature

Naples's weather subtly changes with the onset of September, barely falling from 83.5°F (28.6°C) in August to a still moderately hot 78.1°F (25.6°C). Throughout the nights in September, an average low-temperature of 58.8°F (14.9°C) is noted.

Humidity

In September, the average relative humidity is 74%.

Rainfall

In Naples, in September, during 12.2 rainfall days, 2.64" (67mm) of precipitation is typically accumulated. In Naples, during the entire year, the rain falls for 155.4 days and collects up to 31.69" (805mm) of precipitation.

Snowfall

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

Daylight

In Naples, the average length of the day in September is 12h and 26min.
On the first day of September in Naples, sunrise is at 6:31 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:45 pm CDT.

Sunshine

The average sunshine in September is 9.4h.

UV index

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.
Note: In September, a daily UV index of 5 turns into the following recommendations:
Exercise prevention - Warding off sunburn is urged. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
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Frequently asked questions

What are the temperatures in Naples in September?

In September, the average high-temperature and low-temperature in Naples are 78.1°F (25.6°C) and 58.8°F (14.9°C) respectively. The average heat index (a.k.a. 'apparent temperature', 'real feel'), which combines relative humidity and air temperature, in August is appraised at 91.4°F (33°C).

What is the average humidity in September in Naples?

The average relative humidity in September in Naples, Illinois, is 74%.

How many days does it rain in September in Naples?

In Naples, Illinois, in September, it is raining for 12.2 days, with typically 2.64" (67mm) of accumulated precipitation.

When it does not snow in Naples?

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

Does it snow in Naples in September?

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

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

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

When is the sunrise / sunset in September in Naples?

In September, on the first day of the month, sunrise is at 6:31 am and sunset at 7:33 pm. On the last day of the month, in Naples, Illinois, sunrise is at 6:58 am and sunset at 6:45 pm CDT.

How long on average sun shines in September in Naples?

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

What is the UV index reading in September in Naples?

In September, the average daily maximum UV index in Naples, Illinois, is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability 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
Naples, IL

Average temperature in September - Naples, IL
  • Average high temperature in September: 78.1°F

The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (33.8°F).

  • Average low temperature in September: 58.8°F

The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).

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Average pressure in September
Naples, IL

Average pressure in September - Naples, 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).

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Average wind speed in September
Naples, IL

Average wind speed in September - Naples, IL
  • Average wind speed in September: 6.8mph

The windiest months (with the highest average wind speed) are January and April (9.9mph).
The calmest month (with the lowest average wind speed) is July (6mph).

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Average humidity in September
Naples, IL

Average humidity in September - Naples, IL
  • Average humidity in September: 74%

The month with the highest relative humidity is July (82%).
The month with the lowest relative humidity is October (71%).

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Average rainfall in September
Naples, IL

Average rainfall in September - Naples, IL
  • Average rainfall in September: 2.64"

The wettest month (with the highest rainfall) is May (4.02").
The driest months (with the least rainfall) are January, February and December (1.73").

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Average rainfall days in September
Naples, IL

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

The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is February (7.2 days).

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Average snowfall in September
Naples, IL

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

The month with the highest snowfall is January (3.46").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
Naples, IL

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

The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Naples, IL
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
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 June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).

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Average sunshine days in September
Naples, IL

Average sunshine days in September - Naples, IL
  • Average sunshine days in September: 15.4 days

The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is June (8.6 days).

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Average UV index in September
Naples, IL

Average UV index in September - Naples, 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).

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Average cloud cover in September
Naples, IL

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

The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 30).

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Average visibility in September
Naples, IL

Average visibility in September - Naples, 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).

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Naples, Illinois, USA

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