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 shift into September reveals an average high-temperature of a still moderately hot 75.4°F (24.1°C), closely mirroring August's climate. Throughout September, an average low-temperature of 56.3°F (13.5°C) is expected in Green Rock, Illinois.Humidity
In September, the average relative humidity in Green Rock is 76%.Rainfall
In Green Rock, in September, it is raining for 6.9 days, with typically 0.75" (19mm) of accumulated precipitation. Throughout the year, in Green Rock, there are 99.4 rainfall days, and 9.57" (243mm) of precipitation is accumulated.Snowfall
January through April, September through December are months with snowfall. September is the first month it typically snows in Green Rock. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, in Green Rock, there are 24.5 snowfall days, and 4.09" (104mm) of snow is accumulated.Daylight
The average length of the day in September in Green Rock is 12h and 28min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:33 pm. On the last day of September, in Green Rock, sunrise is at 6:57 am and sunset at 6:44 pm CDT.
Sunshine
In Green Rock, Illinois, the average sunshine in September is 9.1h.UV index
The average daily maximum UV index in September in Green Rock is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Experience reduced UV exposure by about half when donning a wide-brim hat. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Frequently asked questions
What are the temperatures in Green Rock in September?
What is the average humidity in September in Green Rock?
How much does it rain in Green Rock in September?
When does it start to snow in Green Rock?
How many hours of daylight does Green Rock have in September?
When are sunrise and sunset in September in Green Rock?
How long on average sun shines in September in Green Rock?
How high is the UV index in September in Green Rock?
Average temperature in September
Green Rock, IL
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (15.4°F).
Average pressure in September
Green Rock, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Green Rock, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in September
Green Rock, IL
- Average humidity in September: 76%
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Green Rock, IL
- Average rainfall in September: 0.75"
The wettest month (with the highest rainfall) is May (1.61").
The driest month (with the least rainfall) is December (0.35").
Average rainfall days in September
Green Rock, IL
- Average rainfall days in September: 6.9 days
The month with the highest number of rainy days is May (13.4 days).
The month with the least rainy days is January (3.2 days).
Average snowfall in September
Green Rock, IL
- Average snowfall in September: 0.04"
The month with the highest snowfall is January (1.26").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Green Rock, IL
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (7.2 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Green Rock, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Green Rock, IL
- Average sunshine days in September: 20.9 days
The month with the most sunshine days is December (22.4 days).
The month with the least sunshine days is June (14.4 days).
Average UV index in September
Green Rock, IL
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Green Rock, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Green Rock, 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).
Green Rock, Illinois, USA
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