September weather forecastRockdale, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Rockdale, Illinois, with an average temperature varying between 56.7°F (13.7°C) and 74.7°F (23.7°C).Temperature
Rockdale's transition into September involves a gentle shift in temperature, receding from a warm 80.1°F (26.7°C) in August to a still moderately hot 74.7°F (23.7°C). In September, Rockdale experiences a temperature dip to an average of 56.7°F (13.7°C) at night.Humidity
In Rockdale, the average relative humidity in September is 78%.Rainfall
In September, the rain falls for 12.5 days. Throughout September, 2.48" (63mm) of precipitation is accumulated. Throughout the year, there are 153.6 rainfall days, and 32.72" (831mm) of precipitation is accumulated.Snowfall
In Rockdale, Illinois, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:19 am and sunset at 7:25 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:35 pm CDT.
Sunshine
In September, the average sunshine is 8.5h.UV index
The average daily maximum UV index in September in Rockdale is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 4 translates into these guidelines:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rockdale, IL
- Average high temperature in September: 74.7°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in September: 56.7°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 (17.4°F).
Average pressure in September
Rockdale, 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 (29.92"Hg).
Average wind speed in September
Rockdale, IL
- Average wind speed in September: 6.9mph
The windiest month (with the highest average wind speed) is April (9.7mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in September
Rockdale, IL
- Average humidity in September: 78%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Rockdale, IL
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is May (4.41").
The driest month (with the least rainfall) is February (1.61").
Average rainfall days in September
Rockdale, IL
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is February (5.7 days).
Average snowfall in September
Rockdale, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.33").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Rockdale, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.9 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
Rockdale, IL
- Average daylight in September: 12h and 30min
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: 8h and 30min
The month with the most sunshine is August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Rockdale, IL
- Average sunshine days in September: 15 days
The month with the most sunshine days is November (18.1 days).
The month with the least sunshine days is June (10.4 days).
Average UV index in September
Rockdale, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Rockdale, IL
- Average cloud cover in September: 34
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 34).
Average visibility in September
Rockdale, 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).
