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
Stonington's entry into September measures an average high-temperature of a still warm 77.4°F (25.2°C), closely parallel to the preceding month. September generally records an average low-temperature of 58.8°F (14.9°C).Humidity
In Stonington, the average relative humidity in September is 75%.Rainfall
In Stonington, in September, during 12.3 rainfall days, 2.17" (55mm) of precipitation is typically accumulated. In Stonington, during the entire year, the rain falls for 147.7 days and collects up to 29.65" (753mm) of precipitation.Snowfall
In Stonington, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:25 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:52 am and sunset at 6:40 pm CDT.
Sunshine
In September, the average sunshine in Stonington is 9.2h.UV index
In Stonington, Illinois, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: The daily high UV index of 5 during September translates into the following recommendations:
Make use of precautions - Suggestions to resist sunburn are communicated. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Stonington in September?
What is the average humidity in September in Stonington?
How much does it rain in Stonington in September?
When it does not snow in Stonington?
How many hours of daylight does Stonington have in September?
When is the sunrise / sunset in September in Stonington?
How long on average sun shines in September in Stonington?
What is the UV index intensity in September in Stonington?
Average temperature in September
Stonington, IL
- Average high temperature in September: 77.4°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in September: 58.8°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in September
Stonington, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Stonington, IL
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).
Average humidity in September
Stonington, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Stonington, IL
- Average rainfall in September: 2.17"
The wettest month (with the highest rainfall) is April (3.58").
The driest months (with the least rainfall) are February and December (1.65").
Average rainfall days in September
Stonington, IL
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is February (7.1 days).
Average snowfall in September
Stonington, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.8").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Stonington, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.8 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
Stonington, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Stonington, IL
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is November (18.2 days).
The month with the least sunshine days is June (11 days).
Average UV index in September
Stonington, IL
- Average UV index in September: 5
The months with the highest UV index are 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
Stonington, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are June, August and September (Cloud cover 30).
Average visibility in September
Stonington, 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).
Stonington, Illinois, USA
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