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 experiences an average high-temperature of a still tropical 88.2°F (31.2°C), barely different from July's 88.9°F (31.6°C). Knoxville documents a substantial shift from daytime warmth, recording an average nighttime temperature of 65.5°F (18.6°C) in August.

Heat index

In August, the average heat index is computed to be a sweltering 100.4°F (38°C). Adopt heightened safety measures, heat cramps and heat exhaustion may occur. Sustained activity might cause heatstroke.
Heat index details are generally centered around shaded locations and a mild breeze. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is an estimation of the warmth sensation when considering humidity levels. An individual's perception of weather can be swayed by a variety of elements including metabolic differences, pregnancy status, and their level of physical exertion. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Typically, young kids are at a higher risk than adults since they sweat less. Also, the larger skin surface in proportion to their small bodies and the heightened heat production due to their active nature adds to their vulnerability.
The body's innate mechanism to counteract overheating is through perspiration, as it leverages the cooling effects of sweat evaporation. Heightened relative humidity interferes with the body's usual cooling mechanism by reducing evaporation, subsequently decreasing the body's cooling rate and increasing the sensation of heat. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.

Humidity

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

Rainfall

In Knoxville, in August, during 14.3 rainfall days, 2.01" (51mm) of precipitation is typically accumulated. Throughout the year, there are 148.9 rainfall days, and 29.57" (751mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

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

Sunshine

The average sunshine in August 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 estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: The daily high UV index of 6 in August translates into this advice:
Guard oneself from overexposure. Defence against sun injury is vital. The Sun's UV radiation is most potent between the hours of 10 a.m. and 4 p.m. Try to avoid direct sunlight during this time. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.

Frequently asked questions

How hot is August in Knoxville?

August temperatures vary between a high-temperature of 88.2°F (31.2°C) and a low-temperature of 65.5°F (18.6°C). In August, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is computed to be 100.4°F (38°C).

What is the least humid month?

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

What is the average humidity in August?

The average relative humidity in August is 70%.

How much does it rain in August?

In Knoxville, in August, during 14.3 rainfall days, 2.01" (51mm) of precipitation is typically accumulated.

When it does not snow in Knoxville?

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

What is the average length of the day in August?

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

When are sunrise and sunset in August?

In August, on the first day of the month, 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 many hours of sunshine does Knoxville have in August?

The average sunshine duration in August is 9.9h.

When is the highest UV index?

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

What is the UV index reading in August?

In Knoxville, Tennessee, the average daily maximum UV index in August is 6. A UV Index value of 6 to 7 symbolizes a high health risk 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).

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).

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).

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%).

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").

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).

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").

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).

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).

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).

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).

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).

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).

Knoxville, Tennessee, USA

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