September weather forecast
Knoxville, AL

Share

Weather in September

September, the first month of the autumn in Knoxville, is also a hot month, with an average temperature varying between 66.9°F (19.4°C) and 86.9°F (30.5°C).

Temperature

Knoxville measures an average high-temperature of a still hot 86.9°F (30.5°C) in September, nearly consistent with the preceding month. Throughout September nights, Knoxville experiences a consistent temperature average of 66.9°F (19.4°C).

Heat index

The heat index in September is calculated to be a very hot 98.6°F (37°C). Adopt extra preventive measures, the occurrence of heat cramps and heat exhaustion is likely. Heatstroke may follow extended activity.
Be advised, the heat index considers values for conditions in shade and with a light breeze. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', determines the feeling of heat when you account for the relative humidity. The impact of weather is personal, differing among a variety of people based on differences in body mass, height, and the level of physical exertion. The sun, when shining directly, can have a significant impact on the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
Normally, the human body cools itself through perspiration, which removes excessive heat by evaporating sweat. Excessive relative humidity disturbs the body's typical cooling process by reducing evaporation, leading to a decrease in body cooling rate and an increase in the sensation of warmth. When body heat isn't effectively managed, risks of dehydration and overheating amplify.

Humidity

The average relative humidity in September is 72%.

Rainfall

In September, in Knoxville, the rain falls for 13.5 days. Throughout September, 2.32" (59mm) of precipitation is accumulated. Throughout the year, in Knoxville, there are 166.5 rainfall days, and 39.41" (1001mm) of precipitation is accumulated.

Snowfall

In Knoxville, Alabama, snow does not fall in March through November.

Daylight

In September, the average length of the day in Knoxville is 12h and 22min.
On the first day of the month, sunrise is at 6:26 am and sunset at 7:15 pm. On the last day of September, in Knoxville, Alabama, sunrise is at 6:45 am and sunset at 6:36 pm CDT.

Sunshine

In September, the average sunshine in Knoxville is 9.1h.

UV index

The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for average individuals.
Note: The maximum daily UV index, 6 in September, converts into the following recommendations:
Eschew overexposure. Those with light skin may suffer burns in fewer than 20 minutes. Stay in the shade and limit direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is particularly strong. Remember, however, that shade structures may not provide complete protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
[Resources]

Frequently asked questions

Is it hot in Knoxville during September?

During September, Knoxville experiences an average high-temperature of 86.9°F (30.5°C) and a low-temperature of 66.9°F (19.4°C). In September, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is calculated to be 98.6°F (37°C).

What is the average humidity in September in Knoxville?

The average relative humidity in September in Knoxville is 72%.

How many days does it rain in September in Knoxville?

In Knoxville, Alabama, in September, it is raining for 13.5 days, with typically 2.32" (59mm) of accumulated precipitation.

When it does not snow in Knoxville?

In Knoxville, snow does not fall in March through November.

How many hours of daylight does Knoxville have in September?

In September, the average day length in Knoxville is 12h and 22min.

What time are sunrise and sunset in September in Knoxville?

In September, on the first day of the month, sunrise is at 6:26 am and sunset at 7:15 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:36 pm CDT.

How many hours of sunshine does Knoxville have in September?

In September, the average sunshine duration is 9.1h.

How high is the UV index in September in Knoxville?

In September, the average daily maximum UV index is 6. A UV Index of 6 to 7 symbolizes a high hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Knoxville, AL

Average temperature in September - Knoxville, AL
  • Average high temperature in September: 86.9°F

The warmest month (with the highest average high temperature) is July (91.9°F).
The month with the lowest average high temperature is January (52.9°F).

  • Average low temperature in September: 66.9°F

The months with the highest average low temperature are July and August (71.6°F).
The coldest month (with the lowest average low temperature) is January (37.4°F).

[Resources]

Average pressure in September
Knoxville, AL

Average pressure in September - Knoxville, AL
  • Average pressure in September: 30"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).

[Resources]

Average wind speed in September
Knoxville, AL

Average wind speed in September - Knoxville, AL
  • Average wind speed in September: 5.1mph

The windiest month (with the highest average wind speed) is February (7.2mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).

[Resources]

Average humidity in September
Knoxville, AL

Average humidity in September - Knoxville, AL
  • Average humidity in September: 72%

The month with the highest relative humidity is December (80%).
The month with the lowest relative humidity is October (69%).

[Resources]

Average rainfall in September
Knoxville, AL

Average rainfall in September - Knoxville, AL
  • Average rainfall in September: 2.32"

The wettest month (with the highest rainfall) is April (4.29").
The driest month (with the least rainfall) is October (2.28").

[Resources]

Average rainfall days in September
Knoxville, AL

Average rainfall days in September - Knoxville, AL
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is July (20.6 days).
The month with the least rainy days is November (8.5 days).

[Resources]

Average snowfall in September
Knoxville, AL

Average snowfall in September - Knoxville, AL
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.55").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").

[Resources]

Average snowfall days in September
Knoxville, AL

Average snowfall days in September - Knoxville, AL
  • Average snowfall days in September: 0 days

The months with the highest number of snowfall days are January and February (0.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

[Resources]

Average daylight in September /
Average sunshine in September
Knoxville, AL

Average daylight in September / Average sunshine in September - Knoxville, AL
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).

  • Average sunshine in September: 9h and 1min

The month with the most sunshine is June (Average sunshine: 10h and 30min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).

[Resources]

Average sunshine days in September
Knoxville, AL

Average sunshine days in September - Knoxville, AL
  • Average sunshine days in September: 14.8 days

The month with the most sunshine days is October (20.5 days).
The month with the least sunshine days is July (8.8 days).

[Resources]

Average UV index in September
Knoxville, AL

Average UV index in September - Knoxville, AL
  • Average UV index in September: 6

The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, February and December (UV index 3).

[Resources]

Average cloud cover in September
Knoxville, AL

Average cloud cover in September - Knoxville, AL
  • Average cloud cover in September: 29

The months with the most cloud cover are February and December (Cloud cover 48).
The month with the least cloud cover is September (Cloud cover 29).

[Resources]

Average visibility in September
Knoxville, AL

Average visibility in September - Knoxville, AL
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

[Resources]

Knoxville, Alabama, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location