Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The onset of September aligns with a soft reduction in the average high-temperature, gently falling from a warm 79.2°F (26.2°C) in August to a still moderately hot 73.8°F (23.2°C). September brings an average low-temperature of 55.4°F (13°C) to Big Rock.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. Throughout the year, there are 156.4 rainfall days, and 30.98" (787mm) of precipitation is accumulated.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 the month, sunrise is at 6:20 am and sunset at 7:27 pm. On the last day of September, sunrise is at 6:50 am and sunset at 6:37 pm CDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum high UV index of 4 in September translates into the following recommendations:
Exercise prevention - Warding off sunburn is urged. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Big Rock have in September?
When are sunrise and sunset in September?
How many hours of sunshine does Big Rock have in September?
How high is the UV index in September?
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).
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).
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).
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%).
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").
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).
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").
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).
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).
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).
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).
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).
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).
Big Rock, Illinois, USA
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