September weather forecast
Chattanooga, TN

Panorama of the area of Chattanooga, Tennessee
Panorama of the area of Chattanooga, Tennessee

Weather in September

The first month of the autumn, September, is still a warm month in Chattanooga, Tennessee, with an average temperature varying between 81.9°F (27.7°C) and 61.2°F (16.2°C).

Temperature

In Chattanooga, the average high-temperature in September slightly decreases from a tropical 87.3°F (30.7°C) in August to a moderately hot 81.9°F (27.7°C). The average low-temperature, in September, is 61.2°F (16.2°C).

Heat index

In September, the average heat index is estimated at a hot 87.4°F (30.8°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'real feel', 'felt air temperature', or 'feels like', is a measure of how hot it feels when the actual air humidity is factored in. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (pregnancy, clothing, differences in body mass, height, and shape). Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

In September, the average relative humidity in Chattanooga is 76%.

Rainfall

The month with the least rainfall in Chattanooga 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

In Chattanooga, the average length of the day in September is 12h and 23min.
On the first day of September in Chattanooga, sunrise is at 7:14 am and sunset at 8:08 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 7:26 pm EDT.

Sunshine

In September, the average sunshine is 8.3h.

UV index

The average daily maximum UV index in September in Chattanooga is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.
Note: The average daily UV index of 5 in September transform into the following instructions:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. 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. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in September in Chattanooga?

The average high-temperature, in September, in Chattanooga, Tennessee, is 81.9°F (27.7°C), while the average low-temperature is 61.2°F (16.2°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which factors the actual air temperature with the relative humidity, in September is estimated at 87.4°F (30.8°C).

What is the average humidity in September in Chattanooga?

In Chattanooga, the average relative humidity in September is 76%.

What is the driest month in Chattanooga?

September is the month with the least rainfall in Chattanooga. Rain falls for 12.5 days and accumulates 2.56" (65mm) of precipitation.

How many days does it rain in September in Chattanooga?

In Chattanooga, in September, it is raining for 12.5 days, with typically 2.56" (65mm) of accumulated precipitation.

When it does not snow in Chattanooga?

May through October are months without snowfall in Chattanooga, Tennessee.

How many hours of daylight does Chattanooga have in September?

In September, the average day length is 12h and 23min.

What time are sunrise and sunset in September in Chattanooga?

In September, on the first day of the month, sunrise is at 7:14 am and sunset at 8:08 pm. On the last day of the month, in Chattanooga, sunrise is at 7:35 am and sunset at 7:26 pm EDT.

How long on average sun shines in September in Chattanooga?

The average sunshine duration in September in Chattanooga, Tennessee, is 8.3h.

How high is the UV index in September in Chattanooga?

In Chattanooga, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from unsafe exposure to Sun's UV rays.

Average temperature in September
Chattanooga, TN

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).

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Average pressure in September
Chattanooga, TN

Average pressure in September - Chattanooga, TN
  • Average pressure in September: 30.03"

The month with the highest atmospheric pressure is January (30.17").
The month with the lowest atmospheric pressure is June (29.98").

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Average wind speed in September
Chattanooga, TN

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).

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Average humidity in September
Chattanooga, TN

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%).

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Average rainfall in September
Chattanooga, TN

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").

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Average rainfall days in September
Chattanooga, TN

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).

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Average snowfall in September
Chattanooga, TN

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").

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Average snowfall days in September
Chattanooga, TN

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).

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Average daylight in September /
Average sunshine in September
Chattanooga, TN

Average daylight in September / Average sunshine in September - Chattanooga, TN
  • Average daylight in September: 12h and 23min

The month with the longest days is June (Average daylight: 14h and 29min).
The month with the shortest days is December (Average daylight: 9h and 51min).

  • Average sunshine in September: 8.3h

The month with the most sunshine is June (Average sunshine: 10.3h).
The month with the least sunshine is December (Average sunshine: 4.9h).

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Average sunshine days in September
Chattanooga, TN

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).

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Average UV index in September
Chattanooga, TN

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).

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Average cloud cover in September
Chattanooga, TN

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).

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Average visibility in September
Chattanooga, TN

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).

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