September weather forecast
Raritan, IL

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Weather in September

The first month of the autumn, September, is still a warm month in Raritan, Illinois, with an average temperature varying between 76.8°F (24.9°C) and 57.4°F (14.1°C).

Temperature

Raritan in September undergoes a slight reduction in the average high-temperature, shifting from August's 82.2°F (27.9°C) to a still warm 76.8°F (24.9°C). An average low-temperature of 57.4°F (14.1°C) marks the month of September.

Humidity

The average relative humidity in September in Raritan is 75%.

Rainfall

In Raritan, in September, it is raining for 10.2 days, with typically 1.77" (45mm) of accumulated precipitation. In Raritan, during the entire year, the rain falls for 127.6 days and collects up to 21.02" (534mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

In September, the average length of the day is 12h and 27min.
On the first day of the month, sunrise is at 6:31 am and sunset at 7:35 pm. On the last day of September, sunrise is at 6:59 am and sunset at 6:46 pm CDT.

Sunshine

The average sunshine in September is 9.3h.

UV index

The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the average person.
Note: The daily high UV index of 5 in September translates into this advice:
Take precautions - Protection against sun damage is advised. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. 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 is the temperature in September in Raritan?

The high-temperature in Raritan, Illinois, during September is 76.8°F (24.9°C) and the low-temperature is 57.4°F (14.1°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which represents the influence of relative humidity on air temperature, in August is calculated to be 89.6°F (32°C).

What is the average humidity in September in Raritan?

The average relative humidity in September is 75%.

How many days does it rain in September in Raritan?

In September, the rain falls for 10.2 days. Throughout September, 1.77" (45mm) of precipitation is accumulated.

When it does not snow in Raritan?

May through September are months without snowfall.

Does it snow in Raritan in September?

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

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

In September, the average day length in Raritan is 12h and 27min.

When are sunrise and sunset in September in Raritan?

In September, on the first day of the month, sunrise is at 6:31 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:46 pm CDT.

How many hours of sunshine does Raritan have in September?

The average sunshine duration in September in Raritan is 9.3h.

What is the UV index intensity in September in Raritan?

The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health risk 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
Raritan, IL

Average temperature in September - Raritan, IL
  • Average high temperature in September: 76.8°F

The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (30.9°F).

  • Average low temperature in September: 57.4°F

The month with the highest average low temperature is July (66.2°F).
The coldest month (with the lowest average low temperature) is January (18.7°F).

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Average pressure in September
Raritan, IL

Average pressure in September - Raritan, 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 (29.9"Hg).

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Average wind speed in September
Raritan, IL

Average wind speed in September - Raritan, IL
  • Average wind speed in September: 7.6mph

The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.7mph).

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Average humidity in September
Raritan, IL

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

The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).

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Average rainfall in September
Raritan, IL

Average rainfall in September - Raritan, IL
  • Average rainfall in September: 1.77"

The wettest month (with the highest rainfall) is May (3.11").
The driest month (with the least rainfall) is January (0.83").

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Average rainfall days in September
Raritan, IL

Average rainfall days in September - Raritan, IL
  • Average rainfall days in September: 10.2 days

The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (4.3 days).

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Average snowfall in September
Raritan, IL

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

The month with the highest snowfall is January (3.15").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
Raritan, IL

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

The month with the highest number of snowfall days is January (8.5 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
Raritan, IL

Average daylight in September / Average sunshine in September - Raritan, 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 18min).

  • Average sunshine in September: 9h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

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Average sunshine days in September
Raritan, IL

Average sunshine days in September - Raritan, IL
  • Average sunshine days in September: 18.4 days

The month with the most sunshine days is December (20 days).
The months with the least sunshine days are May and June (11.8 days).

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Average UV index in September
Raritan, IL

Average UV index in September - Raritan, 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
Raritan, IL

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

The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are August and September (Cloud cover 30).

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Average visibility in September
Raritan, IL

Average visibility in September - Raritan, 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).

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Raritan, Illinois, USA

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