September weather forecast
Big Rock, IL

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Big Rock, Illinois, with an average temperature varying between 73.8°F (23.2°C) and 55.4°F (13°C).

Temperature

September signifies a minor drop in average high-temperature, transitioning from a moderately hot 79.2°F (26.2°C) in August to a still warm 73.8°F (23.2°C). Big Rock in September experiences a low-temperature average of 55.4°F (13°C).

Humidity

In Big Rock, the average relative humidity in September is 79%.

Rainfall

In September, the rain falls for 13 days. Throughout September, 2.28" (58mm) of precipitation is accumulated. In Big Rock, during the entire year, the rain falls for 156.4 days and collects up to 30.98" (787mm) of precipitation.

Snowfall

In Big Rock, snow does not fall in June through September.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of September, sunrise is at 6:20 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm CDT.

Sunshine

In September, the average sunshine in Big Rock is 8.6h.

UV index

In Big Rock, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the average person.
Note: The daily maximum UV index of 4 in September interprets into the following advice:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
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Frequently asked questions

What is the temperature in September in Big Rock?

In Big Rock, 73.8°F (23.2°C) is the average high-temperature and 55.4°F (13°C) is the average low-temperature during September. The average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines relative humidity and air temperature, in July is appraised at 86°F (30°C).

What is the average humidity in September in Big Rock?

In Big Rock, the average relative humidity in September is 79%.

How much does it rain in Big Rock in September?

In Big Rock, Illinois, during September, the rain falls for 13 days and regularly aggregates up to 2.28" (58mm) of precipitation.

When it does not snow in Big Rock?

June through September are months without snowfall in Big Rock, Illinois.

Does it snow in Big Rock in September?

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

What is the average length of the day in September in Big Rock?

The average day length in September in Big Rock is 12h and 28min.

What time are sunrise and sunset in September in Big Rock?

On the first day of September in Big Rock, sunrise is at 6:20 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm CDT.

How long on average sun shines in September in Big Rock?

In September, the average sunshine duration is 8.6h.

How high is the UV index in September in Big Rock?

In September, the average daily maximum UV index is 4. 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
Big Rock, IL

Average temperature in September - Big Rock, IL
  • Average high temperature in September: 73.8°F

The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (27.9°F).

  • Average low temperature in September: 55.4°F

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (15.8°F).

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Average pressure in September
Big Rock, IL

Average pressure in September - Big Rock, 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
Big Rock, IL

Average wind speed in September - Big Rock, IL
  • Average wind speed in September: 7mph

The windiest months (with the highest average wind speed) are January, February and April (9.8mph).
The calmest month (with the lowest average wind speed) is August (6mph).

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Average humidity in September
Big Rock, IL

Average humidity in September - Big Rock, IL
  • Average humidity in September: 79%

The months with the highest relative humidity are January, July and August (84%).
The month with the lowest relative humidity is October (74%).

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Average rainfall in September
Big Rock, IL

Average rainfall in September - Big Rock, IL
  • Average rainfall in September: 2.28"

The wettest month (with the highest rainfall) is May (4.33").
The driest month (with the least rainfall) is December (1.57").

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Average rainfall days in September
Big Rock, IL

Average rainfall days in September - Big Rock, IL
  • Average rainfall days in September: 13 days

The month with the highest number of rainy days is July (18.2 days).
The month with the least rainy days is February (6 days).

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Average snowfall in September
Big Rock, IL

Average snowfall in September - Big Rock, IL
  • Average snowfall in September: 0"

The month with the highest snowfall is January (4.65").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in September
Big Rock, IL

Average snowfall days in September - Big Rock, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (13.1 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
Big Rock, IL

Average daylight in September / Average sunshine in September - Big Rock, 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 4min

The month with the most sunshine is August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

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Average sunshine days in September
Big Rock, IL

Average sunshine days in September - Big Rock, IL
  • Average sunshine days in September: 14.5 days

The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.3 days).

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Average UV index in September
Big Rock, IL

Average UV index in September - Big Rock, IL
  • Average UV index in September: 4

The months with the highest UV index are June, July 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
Big Rock, IL

Average cloud cover in September - Big Rock, IL
  • Average cloud cover in September: 34

The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are August and September (Cloud cover 34).

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Average visibility in September
Big Rock, IL

Average visibility in September - Big Rock, 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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Big Rock, Illinois, USA

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