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 from August to September includes a minor decrease in the average high-temperature, lightly dropping from a moderately hot 78.3°F (25.7°C) to a pleasant 72.7°F (22.6°C). Throughout the nights in September, Rock City experiences an average low-temperature of 54°F (12.2°C).Humidity
In September, the average relative humidity is 80%.Rainfall
In Rock City, in September, it is raining for 11.3 days, with typically 1.46" (37mm) of accumulated precipitation. Throughout the year, there are 138 rainfall days, and 19.69" (500mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In September, the average length of the day 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, 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 value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: A typical high UV index of 4 in September suggests the following recommendations:
Take precautions - Protection against sunburn is recommended. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Rock City have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September in Rock City?
How high is the UV index in September?
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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