September weather forecastDuncan, TN
September
Weather in September
September, the first month of the autumn in Duncan, is still a warm month, with an average temperature varying between 59.9°F (15.5°C) and 81.1°F (27.3°C).Temperature
Duncan's transition into September involves a gentle shift in temperature, receding from a hot 86.7°F (30.4°C) in August to a moderately hot 81.1°F (27.3°C). In September, the average low-temperature records at a mild 59.9°F (15.5°C) during the nights.Heat index
In September, the heat index is evaluated at a tropical 86°F (30°C). Exhaustion might be the outcome of enduring exposure and continuous activity, with a risk of heat cramps.Always consider that heat index estimations are for light winds and places in the shade. Direct exposure to sunshine could lead to a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. Always consider that direct sunlight exposure might heighten the heat's effects, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.
Humidity
In Duncan, the average relative humidity in September is 74%.Rainfall
September is the month with the least rainfall. Rain falls for 10.6 days and accumulates 0.94" (24mm) of precipitation.Snowfall
April through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 23min.On the first day of September, sunrise is at 7:08 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 7:30 am and sunset at 7:20 pm EDT.
Sunshine
In September, the average sunshine in Duncan is 8.7h.UV index
In Duncan, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for average individuals.Note: In September, the UV index of 5 transforms into the following advice:
Preventative actions are necessary - Recommendations to ward off sunburn are given. To avoid the Sun's strongest rays, limit exposure around the mid-day period. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Duncan, TN
- Average high temperature in September: 81.1°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is January (44.8°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (29.5°F).
Average pressure in September
Duncan, TN
- Average pressure in September: 30.04"Hg
The months with the highest atmospheric pressure are January and November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Duncan, TN
- Average wind speed in September: 3.8mph
The windiest month (with the highest average wind speed) is April (5.9mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).
Average humidity in September
Duncan, TN
- Average humidity in September: 74%
The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is August (72%).
Average rainfall in September
Duncan, TN
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is July (2.2").
The driest month (with the least rainfall) is September (0.94").
Average rainfall days in September
Duncan, TN
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is July (16.3 days).
The month with the least rainy days is November (8.7 days).
Average snowfall in September
Duncan, TN
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.98").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in September
Duncan, TN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.4 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
Duncan, TN
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is June (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 5h and 6min).
Average sunshine days in September
Duncan, TN
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is November (19.3 days).
The months with the least sunshine days are February and July (12.5 days).
Average UV index in September
Duncan, TN
- 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 and December (UV index 2).
Average cloud cover in September
Duncan, TN
- Average cloud cover in September: 30
The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility in September
Duncan, TN
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and March (5mi).





