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
September records an average high-temperature of a still warm 75.7°F (24.3°C), indicating a minor variation from the preceding month. An average low-temperature of 56.7°F (13.7°C) is common in Castleton, Illinois, during the nights of September.Humidity
In September, the average relative humidity in Castleton is 77%.Rainfall
In Castleton, in September, during 9.3 rainfall days, 1.1" (28mm) of precipitation is typically accumulated. Throughout the year, there are 116.8 rainfall days, and 13.98" (355mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In September, the average length of the day in Castleton is 12h and 28min.On the first day of September, sunrise is at 6:26 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:41 pm CDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In Castleton, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: A daily maximum UV index of 4 in September translates into the following instructions:
Make use of precautions - Shielding skin and eyes from injury is a requirement. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Castleton?
What is the average humidity in September in Castleton?
How many days does it rain in September in Castleton?
When it does not snow in Castleton?
Does it snow in Castleton in September?
How many hours of daylight does Castleton have in September?
What time are sunrise and sunset in September in Castleton?
How many hours of sunshine does Castleton have in September?
What is the UV index reading in September in Castleton?
Average temperature in September
Castleton, IL
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (29.7°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 (17.8°F).
Average pressure in September
Castleton, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Castleton, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in September
Castleton, IL
- Average humidity in September: 77%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Castleton, IL
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is May (2.24").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in September
Castleton, IL
- Average rainfall days in September: 9.3 days
The month with the highest number of rainy days is May (15.2 days).
The months with the least rainy days are January and February (4.2 days).
Average snowfall in September
Castleton, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.81").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Castleton, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.6 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
Castleton, 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 18min).
- Average sunshine in September: 9h and 1min
The months with the most sunshine are June and July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Castleton, IL
- Average sunshine days in September: 18.3 days
The month with the most sunshine days is November (21.3 days).
The month with the least sunshine days is May (12.8 days).
Average UV index in September
Castleton, 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
Castleton, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in September
Castleton, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Castleton, Illinois, USA
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