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
With the arrival of September, Caseyville's average high-temperature registers at a still warm 79°F (26.1°C), indicating a subtle variation from the previous month. Throughout September, the nighttime temperature averages to a refreshing 59.9°F (15.5°C).Humidity
In September, the average relative humidity in Caseyville is 75%.Rainfall
In Caseyville, in September, it is raining for 12.3 days, with typically 2.13" (54mm) of accumulated precipitation. Throughout the year, there are 149.9 rainfall days, and 33.94" (862mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through March, September, November and December. September is the first month it typically snows in Caseyville. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 20.7 snowfall days, and 7.13" (181mm) of snow is accumulated.Daylight
The average length of the day in September in Caseyville is 12h and 25min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:29 pm. On the last day of September, in Caseyville, sunrise is at 6:55 am and sunset at 6:43 pm CDT.
Sunshine
In Caseyville, the average sunshine in September is 9.3h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 suggests these recommendations:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Frequently asked questions
What is the temperature in September in Caseyville?
What is the average humidity in September in Caseyville?
How many days does it rain in September in Caseyville?
When does it start to snow in Caseyville?
What is the average length of the day in September in Caseyville?
When are sunrise and sunset in September in Caseyville?
How long on average sun shines in September in Caseyville?
How high is the UV index in September in Caseyville?
Average temperature in September
Caseyville, IL
- Average high temperature in September: 79°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Caseyville, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Caseyville, IL
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is January (9.5mph).
The calmest month (with the lowest average wind speed) is July (5.6mph).
Average humidity in September
Caseyville, IL
- Average humidity in September: 75%
The months with the highest relative humidity are May, July and August (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Caseyville, IL
- Average rainfall in September: 2.13"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is February (1.77").
Average rainfall days in September
Caseyville, IL
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in September
Caseyville, IL
- Average snowfall in September: 0.04"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in September
Caseyville, IL
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (7 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Caseyville, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Caseyville, IL
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is December (18.6 days).
The month with the least sunshine days is May (11.6 days).
Average UV index in September
Caseyville, IL
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Caseyville, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are June and August (Cloud cover 28).
Average visibility in September
Caseyville, 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).
Caseyville, Illinois, USA
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