September weather forecastChestnut, IL
September
Weather in September
September, the first month of the autumn in Chestnut, is also a moderately hot month, with an average temperature varying between 77°F (25°C) and 58.5°F (14.7°C).Temperature
September's onset records an average high-temperature of a still warm 77°F (25°C), a near match to August's 81.3°F (27.4°C). Throughout September, Chestnut registers a consistent average low-temperature of 58.5°F (14.7°C).Humidity
In September, the average relative humidity in Chestnut, Illinois, is 76%.Rainfall
In Chestnut, during September, the rain falls for 11.8 days and regularly aggregates up to 1.81" (46mm) of precipitation. In Chestnut, Illinois, during the entire year, the rain falls for 141.8 days and collects up to 22.24" (565mm) of precipitation.Snowfall
In Chestnut, snow does not fall in May through October.Daylight
In September, the average length of the day 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 Chestnut, Illinois, is 9h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: A maximum UV index of 5 in September translates into the following recommendations:
Act with care - Obligation to protect against skin and eye damage is highlighted. When the Sun is at its strongest around midday, find shade and limit exposure. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Remember! The Sun's UV radiation can be magnified almost twofold by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Chestnut, IL
- Average high temperature in September: 77°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in September: 58.5°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (20.5°F).
Average pressure in September
Chestnut, 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
Chestnut, IL
- Average wind speed in September: 7.3mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).
Average humidity in September
Chestnut, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Chestnut, IL
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is May (2.68").
The driest month (with the least rainfall) is December (1.1").
Average rainfall days in September
Chestnut, IL
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is May (17 days).
The months with the least rainy days are January and February (6.3 days).
Average snowfall in September
Chestnut, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.24").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Chestnut, IL
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (9.4 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Chestnut, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Chestnut, IL
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in September
Chestnut, IL
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Chestnut, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are June and September (Cloud cover 31).
Average visibility in September
Chestnut, 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).
