September weather forecastChattanooga, TN
September
Weather in September
September marks the transition from summer to fall in Chattanooga. Although it entails a considerable decrease from the summer highs, September’s temperatures remain warm, providing ideal conditions for outdoor pursuits. The reduced rainfall in this month, which is 2.56" (65mm), is balanced out by comfortable weather conditions. As the month transitions into October, the city braces for cooler temperatures and a notable change in the weather pattern.Temperature
Start of September brings a slight shift in the average high-temperature, dipping a bit from August's tropical 87.3°F (30.7°C) to a warm 81.9°F (27.7°C). The nighttime temperature dips to an enjoyable 61.2°F (16.2°C) on average during September.Heat index
The heat index in September is estimated at a hot 87.8°F (31°C). If one persists in activity during exposure, it could induce weariness and subsequently, heat cramps.The standards for the heat index are set for locations in shade and under light breezes. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. Keep aware, the sun, when shining directly, can intensify the heat experience, 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 Chattanooga, the average relative humidity in September is 76%.Rainfall
The month with the least rainfall in Chattanooga, Tennessee, is September, when the rain falls for 12.5 days and typically collects 2.56" (65mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 7:14 am and sunset at 8:07 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 7:26 pm EDT.
Sunshine
In Chattanooga, Tennessee, the average sunshine in September is 8.3h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for the average person.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Chattanooga, TN
- Average high temperature in September: 81.9°F
The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (46°F).
- Average low temperature in September: 61.2°F
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (30.7°F).
Average pressure in September
Chattanooga, TN
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Chattanooga, TN
- Average wind speed in September: 4.1mph
The windiest month (with the highest average wind speed) is February (6.4mph).
The calmest month (with the lowest average wind speed) is August (3.8mph).
Average humidity in September
Chattanooga, TN
- Average humidity in September: 76%
The month with the highest relative humidity is December (80%).
The months with the lowest relative humidity are June, July, August, October and November (75%).
Average rainfall in September
Chattanooga, TN
- Average rainfall in September: 2.56"
The wettest month (with the highest rainfall) is December (4.37").
The driest month (with the least rainfall) is September (2.56").
Average rainfall days in September
Chattanooga, TN
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is July (19.6 days).
The month with the least rainy days is November (9.8 days).
Average snowfall in September
Chattanooga, TN
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.85").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Chattanooga, TN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.1 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Chattanooga, 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 18min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 4h and 54min).
Average sunshine days in September
Chattanooga, TN
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is October (18.9 days).
The month with the least sunshine days is July (9.4 days).
Average UV index in September
Chattanooga, 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 and December (UV index 2).
Average cloud cover in September
Chattanooga, TN
- Average cloud cover in September: 33
The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is June (Cloud cover 31).
Average visibility in September
Chattanooga, TN
- Average visibility in September: 5mi
The months with the highest visibility are June, October and November (6mi).
The months with the lowest visibility are January, February, March, April, May, July, August, September and December (5mi).
