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
Rock City's progression into September involves a gentle drop in the average high-temperature, from a warm 78.3°F (25.7°C) in August to an agreeable 72.7°F (22.6°C). Nightly temperatures drop to an average low of 54°F (12.2°C) in September.Humidity
In Rock City, the average relative humidity in September is 80%.Rainfall
In Rock City, Illinois, during September, the rain falls for 11.3 days and regularly aggregates up to 1.46" (37mm) of precipitation. In Rock City, during the entire year, the rain falls for 138 days and collects up to 19.69" (500mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September in Rock City, Illinois, is 12h and 28min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:31 pm. On the last day of September, in Rock City, sunrise is at 6:54 am and sunset at 6:40 pm CDT.
Sunshine
In September, the average sunshine is 8.9h.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 unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Exercise prevention - Warding off sunburn is urged. To protect against the Sun's most potent rays, avoid direct exposure around midday. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Frequently asked questions
What are September temperatures in Rock City?
What is the average humidity in September in Rock City?
How much does it rain in Rock City in September?
When it does not snow in Rock City?
Does it snow in Rock City in September?
What is the average length of the day in September in Rock City?
When is the sunrise / sunset in September in Rock City?
How many hours of sunshine does Rock City have in September?
What is the UV index reading in September in Rock City?
Average temperature in September
Rock City, IL
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (25.2°F).
- Average low temperature in September: 54°F
The month with the highest average low temperature is July (62.8°F).
The coldest month (with the lowest average low temperature) is January (13.1°F).
Average pressure in September
Rock City, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Rock City, IL
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Rock City, IL
- Average humidity in September: 80%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
Rock City, IL
- Average rainfall in September: 1.46"
The wettest month (with the highest rainfall) is June (2.87").
The driest month (with the least rainfall) is December (0.83").
Average rainfall days in September
Rock City, IL
- Average rainfall days in September: 11.3 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is January (4.9 days).
Average snowfall in September
Rock City, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.99").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Rock City, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rock City, 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 6min).
- Average sunshine in September: 8h and 5min
The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Rock City, IL
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is November (17.7 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in September
Rock City, IL
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Rock City, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in September
Rock City, IL
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, February, July and August (5mi).
Rock City, Illinois, USA
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