August weather forecast
Knoxville, TN

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The scenic scape of the little town of Knoxville in Tennessee
The scenic scape of the little town of Knoxville in Tennessee

Weather in August

Heatwaves start to subside, as Knoxville's August weather sees a slight dip in temperature compared to July. The transition month from peak summer to early fall is marked by hot but bearable climates. Though rainfall is at annual low, the decreased humidity ensures an enjoyable outdoor setting. August serves as a period of gradual cold anticipation, setting the stage for fall in Knoxville. The month's weather still accommodates outdoor activities, making it an idyllic time for picnics and recreational pursuits.

Temperature

August's onset in Knoxville, Tennessee, brings an average high-temperature of a still tropical 88.2°F (31.2°C), showing a minute difference from July's 88.9°F (31.6°C). Knoxville's average nighttime temperatures present a clear contrast to its daytime highs, measured at a refreshing 65.5°F (18.6°C) in August.

Heat index

During August, the heat index is appraised at a fiery hot 100.4°F (38°C). Take more preventive steps, risk of heat exhaustion and heat cramps is elevated. Long activity may culminate in heatstroke.
Given the heat index, its values are aligned with shaded sites and gentle winds. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'real feel' or 'felt air temperature', integrates the air's temperature and its humidity to showcase the felt temperature by people. The effect of weather is individual, with a variety of people experiencing it differently due to distinctions in body mass, height, and level of activity. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
To combat high temperatures, the human body perspires and relies on sweat evaporation for cooling. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. If heat absorption isn't effectively countered by the body's cooling methods, body temperature surges, hinting at potential problems.

Humidity

August is the least humid month, with an average relative humidity of 70%.

Rainfall

In Knoxville, during August, the rain falls for 14.3 days and regularly aggregates up to 2.01" (51mm) of precipitation. Throughout the year, in Knoxville, Tennessee, there are 148.9 rainfall days, and 29.57" (751mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

The average length of the day in August in Knoxville is 13h and 29min.
On the first day of August in Knoxville, sunrise is at 6:43 am and sunset at 8:40 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 8:04 pm EDT.

Sunshine

In August, the average sunshine is 9.9h.

UV index

May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: The UV index of 6 during August leads to these advisories:
Guard against overexposure. Protection from sun-induced harm is essential. Between 10 a.m. and 4 p.m., the Sun emits the most powerful UV radiation. Limit direct exposure to the Sun during these hours. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
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Frequently asked questions

How hot does it get in Knoxville in August?

In Knoxville, 88.2°F (31.2°C) is the average high-temperature and 65.5°F (18.6°C) is the average low-temperature during August. The average heat index (a.k.a. 'felt air temperature', 'real feel'), which calculates the temperature value influenced by the moisture in the air, in August is appraised at 100.4°F (38°C).

What is the least humid month in Knoxville?

The least humid month in Knoxville is August, with an average relative humidity of 70%.

What is the average humidity in August in Knoxville?

In Knoxville, the average relative humidity in August is 70%.

How much does it rain in Knoxville in August?

In August, in Knoxville, the rain falls for 14.3 days. Throughout August, 2.01" (51mm) of precipitation is accumulated.

When it does not snow in Knoxville?

In Knoxville, Tennessee, snow does not fall in May through October.

What is the average length of the day in August in Knoxville?

In Knoxville, the average day length in August is 13h and 29min.

When are sunrise and sunset in August in Knoxville?

On the first day of August in Knoxville, sunrise is at 6:43 am and sunset at 8:40 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 8:04 pm EDT.

How long on average sun shines in August in Knoxville?

The average sunshine duration in August in Knoxville is 9.9h.

What is the month with the highest UV index in Knoxville?

The months with the highest UV index in Knoxville are May through August, with an average maximum UV index of 6.

How high is the UV index in August in Knoxville?

In August, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high hazard to health 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 August
Knoxville, TN

Average temperature in August - Knoxville, TN
  • Average high temperature in August: 88.2°F

The warmest month (with the highest average high temperature) is July (88.9°F).
The month with the lowest average high temperature is January (44.8°F).

  • Average low temperature in August: 65.5°F

The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (29.3°F).

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Average pressure in August
Knoxville, TN

Average pressure in August - Knoxville, TN
  • Average pressure in August: 30.01"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).

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Average wind speed in August
Knoxville, TN

Average wind speed in August - Knoxville, TN
  • Average wind speed in August: 3.8mph

The windiest month (with the highest average wind speed) is April (6mph).
The calmest month (with the lowest average wind speed) is August (3.8mph).

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Average humidity in August
Knoxville, TN

Average humidity in August - Knoxville, TN
  • Average humidity in August: 70%

The months with the highest relative humidity are February and December (78%).
The month with the lowest relative humidity is August (70%).

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Average rainfall in August
Knoxville, TN

Average rainfall in August - Knoxville, TN
  • Average rainfall in August: 2.01"

The wettest month (with the highest rainfall) is February (3.66").
The driest month (with the least rainfall) is September (1.5").

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Average rainfall days in August
Knoxville, TN

Average rainfall days in August - Knoxville, TN
  • Average rainfall days in August: 14.3 days

The month with the highest number of rainy days is July (16.2 days).
The month with the least rainy days is November (8.4 days).

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Average snowfall in August
Knoxville, TN

Average snowfall in August - Knoxville, TN
  • Average snowfall in August: 0"

The month with the highest snowfall is February (1.57").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in August
Knoxville, TN

Average snowfall days in August - Knoxville, TN
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (3.8 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 August /
Average sunshine in August
Knoxville, TN

Average daylight in August / Average sunshine in August - Knoxville, TN
  • Average daylight in August: 13h and 3min

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 48min).

  • Average sunshine in August: 9h and 5min

The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 54min).

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Average sunshine days in August
Knoxville, TN

Average sunshine days in August - Knoxville, TN
  • Average sunshine days in August: 14.6 days

The month with the most sunshine days is October (20.5 days).
The month with the least sunshine days is July (12.9 days).

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Average UV index in August
Knoxville, TN

Average UV index in August - Knoxville, TN
  • Average UV index in August: 6

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).

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Average cloud cover in August
Knoxville, TN

Average cloud cover in August - Knoxville, TN
  • Average cloud cover in August: 29

The month with the most cloud cover is February (Cloud cover 54).
The month with the least cloud cover is June (Cloud cover 28).

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Average visibility in August
Knoxville, TN

Average visibility in August - Knoxville, TN
  • Average visibility in August: 6mi

The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).

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Knoxville, Tennessee, USA

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