September weather forecast
Alcoa, TN

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Weather in September

In September, Alcoa starts embracing the mellow weather of fall, as temperatures begin their gradual descent from summer highs. The city transitions smoothly, combining the last vestiges of summer with the first hints of autumn. Interestingly, September emerges as the month with the least rainfall, recording only 0.94" (24mm) on average. Fall colors begin to deck the landscape, making it an ideal time for leaf-peeping and scenic drives. Gradually, Alcoa starts preparing to bid adieu to the warmth, welcoming the fall with open arms.

Temperature

The onset of September in Alcoa results in a small decrease in the average high-temperature, moderately receding from a tropical 86.7°F (30.4°C) in August to a moderately hot 81.1°F (27.3°C). Alcoa records a mean low-temperature of 59.9°F (15.5°C) in September.

Heat index

During September, the heat index is evaluated at a hot 86°F (30°C). Continuous activity in exposure could lead to a feeling of fatigue and heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Direct sunlight exposure may cause a 15 Fahrenheit (8 Celsius) degrees rise in the heat index.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. Additional elements encompassing metabolic differences, the degree of physical activity, and attire can impact the individual's perception of temperature. 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 extremely significant for babies and toddlers. In general, children are more at risk than adults because they sweat less. Furthermore, the large skin surface compared to their small bodies and the high heat production due to their actions contribute to this vulnerability.

Humidity

In September, the average relative humidity is 74%.

Rainfall

The month with the least rainfall is September, when the rain falls for 10.6 days and typically collects 0.94" (24mm) of precipitation.

Snowfall

In Alcoa, snow does not fall in April through September.

Daylight

The average length of the day in September in Alcoa 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

The average sunshine in September in Alcoa, Tennessee, is 8.7h.

UV index

The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: The maximum daily UV index, 5 in September, converts into the following recommendations:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. 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.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in Alcoa in September?

The high-temperature, in September, in Alcoa, is 81.1°F (27.3°C), while the low-temperature averages to 59.9°F (15.5°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines relative humidity and air temperature, in September is evaluated at 86°F (30°C).

What is the average humidity in September in Alcoa?

In Alcoa, the average relative humidity in September is 74%.

What is the driest month in Alcoa?

September is the month with the least rainfall in Alcoa. Rain falls for 10.6 days and accumulates 0.94" (24mm) of precipitation.

How much does it rain in Alcoa in September?

In Alcoa, during September, the rain falls for 10.6 days and regularly aggregates up to 0.94" (24mm) of precipitation.

When it does not snow in Alcoa?

In Alcoa, snow does not fall in April through September.

Does it snow in Alcoa in September?

In Alcoa, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September in Alcoa?

The average day length in September is 12h and 23min.

When are sunrise and sunset in September in Alcoa?

In September, on the first day of the month, sunrise is at 7:08 am and sunset at 8:02 pm. On the last day of the month, in Alcoa, sunrise is at 7:30 am and sunset at 7:20 pm EDT.

How many hours of sunshine does Alcoa have in September?

In September, the average sunshine duration in Alcoa, Tennessee, is 8.7h.

How high is the UV index in September in Alcoa?

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate health threat from exposure to Sun's UV rays.
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
Alcoa, TN

Average temperature in September - Alcoa, 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
Alcoa, TN

Average pressure in September - Alcoa, 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
Alcoa, TN

Average wind speed in September - Alcoa, 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
Alcoa, TN

Average humidity in September - Alcoa, 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
Alcoa, TN

Average rainfall in September - Alcoa, 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
Alcoa, TN

Average rainfall days in September - Alcoa, 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
Alcoa, TN

Average snowfall in September - Alcoa, 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
Alcoa, TN

Average snowfall days in September - Alcoa, 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
Alcoa, TN

Average daylight in September / Average sunshine in September - Alcoa, TN
  • Average daylight in September: 12h and 2min

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 4min

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
Alcoa, TN

Average sunshine days in September - Alcoa, 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
Alcoa, TN

Average UV index in September - Alcoa, 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
Alcoa, TN

Average cloud cover in September - Alcoa, 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
Alcoa, TN

Average visibility in September - Alcoa, 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).

Alcoa, Tennessee, USA

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