August is one of the warmer months of the year in Knoxville, with average highs near 30.9°C and lows around 18.9°C (mean 24.9°C). It is about average for rainfall, averaging 97 mm of rainfall and 69% relative humidity across the period.
August is one of the warmer months of the year in Knoxville. Across 45 years of records, the warmest August in Knoxville was 2007 — when the month averaged 28.2°C — while the coldest was 1989 at 22.9°C. Typical August days reach 30.9°C with nights near 18.9°C. The long-term August temperature trend is broadly flat.
August is about average for rainfall in Knoxville, averaging 97 mm of rainfall. The wettest August on record was 2021 with 236 mm, while the driest was 2007 at 36 mm.
Relative humidity in Knoxville during August averages 69%. The most humid August was 2013 at 81%, and the least humid was 1999 at 56%.
August receives about 5.3 kWh/m²/day of solar energy in Knoxville. The sunniest Augusts were 2011 and 2024 at 6.2 kWh/m²/day, and the cloudiest was 1992 at 4.4.
Average wind speed in Knoxville during August is 0.7 m/s. The windiest Augusts were 1995, 1999 and 2000 at 0.8 m/s, while the calmest were 2021, 2022 and 2025, among others at 0.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 24.7°C | 24.7°C | 25.2°C | 24.9°C | 25.0°C | +0.3°C |
| Avg High | 30.7°C | 30.9°C | 31.3°C | 30.7°C | 30.7°C | 0°C |
| Avg Low | 18.6°C | 18.5°C | 19.1°C | 19.1°C | 19.3°C | +0.7°C |
| Avg Rain | 100 mm | 90 mm | 85 mm | 95 mm | 127 mm | +27 mm |
August temperatures in Knoxville have risen by about 0.6°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 7.7°C (1986) to a record high of 40°C (1983).
Rainfall in August is about average for rainfall, averaging 97 mm, with a wettest year of 236 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0°C per decade while lows rose 0.2°C per decade, narrowing the gap between day and night.
One of the best times to visit Knoxville
August is one of the best times to visit Knoxville. Expect days averaging 30.9°C and nights around 18.9°C (mean 24.9°C) — warmer than Knoxville's yearly average — with higher rainfall (97 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 31.1°C | 24.9°C | 18.7°C | 35.7°C | 12.2°C | 86 mm | 68% | 0.6 m/s | 5.3 |
| 2024 | 31.9°C | 25.3°C | 18.7°C | 37.0°C | 12.1°C | 55 mm | 66% | 0.7 m/s | 6.2 |
| 2023 | 30.1°C | 24.7°C | 19.3°C | 35.4°C | 13.2°C | 158 mm | 75% | 0.7 m/s | 5.5 |
| 2022 | 30.3°C | 24.8°C | 19.4°C | 35.0°C | 15.9°C | 82 mm | 75% | 0.6 m/s | 5.4 |
| 2021 🌧️ | 30.7°C | 25.3°C | 20.0°C | 34.9°C | 15.9°C | 236 mm | 73% | 0.6 m/s | 5.3 |
| 2020 | 30.0°C | 24.8°C | 19.6°C | 33.2°C | 17.1°C | 146 mm | 75% | 0.6 m/s | 5.3 |
| 2019 | 31.0°C | 25.4°C | 19.8°C | 34.9°C | 14.4°C | 87 mm | 70% | 0.6 m/s | 5.9 |
| 2018 | 30.2°C | 24.8°C | 19.5°C | 33.2°C | 12.8°C | 118 mm | 74% | 0.7 m/s | 5.4 |
| 2017 | 29.8°C | 24.0°C | 18.2°C | 34.2°C | 13.6°C | 134 mm | 71% | 0.7 m/s | 5.4 |
| 2016 | 33.0°C | 26.9°C | 20.8°C | 36.7°C | 14.9°C | 85 mm | 69% | 0.7 m/s | 5.6 |
| 2015 | 29.2°C | 23.6°C | 17.9°C | 32.2°C | 11.8°C | 92 mm | 73% | 0.6 m/s | 5.5 |
| 2014 | 30.1°C | 24.3°C | 18.5°C | 34.7°C | 14.4°C | 107 mm | 71% | 0.7 m/s | 5.6 |
| 2013 | 27.9°C | 23.0°C | 18.2°C | 31.8°C | 13.5°C | 96 mm | 81% | 0.6 m/s | 4.9 |
| 2012 | 30.5°C | 24.3°C | 18.1°C | 34.7°C | 13.5°C | 87 mm | 67% | 0.6 m/s | 5.4 |
| 2011 | 32.7°C | 25.8°C | 18.9°C | 36.2°C | 13.7°C | 48 mm | 63% | 0.7 m/s | 6.2 |
| 2010 | 32.7°C | 26.8°C | 20.9°C | 35.9°C | 16.6°C | 101 mm | 70% | 0.6 m/s | 5.5 |
| 2009 | 28.5°C | 23.3°C | 18.1°C | 31.6°C | 13.3°C | 114 mm | 78% | 0.7 m/s | 5.3 |
| 2008 | 31.6°C | 24.8°C | 18.0°C | 35.5°C | 13.1°C | 72 mm | 61% | 0.7 m/s | 5.8 |
| 2007 🔥 | 34.8°C | 28.2°C | 21.5°C | 39.3°C | 18.6°C | 36 mm | 58% | 0.7 m/s | 5.7 |
| 2006 | 32.5°C | 26.4°C | 20.3°C | 36.6°C | 15.6°C | 130 mm | 69% | 0.6 m/s | 5.2 |
| 2005 | 32.2°C | 26.2°C | 20.2°C | 35.3°C | 18.1°C | 89 mm | 68% | 0.7 m/s | 5.1 |
| 2004 | 29.2°C | 23.1°C | 17.1°C | 33.4°C | 10.3°C | 75 mm | 71% | 0.7 m/s | 5.2 |
| 2003 | 29.8°C | 24.7°C | 19.7°C | 34.1°C | 17.3°C | 110 mm | 78% | 0.6 m/s | 5.3 |
| 2002 | 33.1°C | 26.1°C | 19.1°C | 36.8°C | 14.5°C | 59 mm | 60% | 0.7 m/s | 5.5 |
| 2001 | 30.0°C | 24.4°C | 18.8°C | 33.2°C | 13.7°C | 103 mm | 73% | 0.7 m/s | 5 |
| 2000 | 31.4°C | 24.9°C | 18.3°C | 36.3°C | 13.8°C | 62 mm | 65% | 0.8 m/s | 5.3 |
| 1999 | 32.8°C | 25.3°C | 17.8°C | 36.6°C | 11.1°C | 38 mm | 56% | 0.8 m/s | 5.9 |
| 1998 | 32.0°C | 25.2°C | 18.3°C | 35.6°C | 14.6°C | 56 mm | 63% | 0.7 m/s | 5.7 |
| 1997 | 31.0°C | 24.3°C | 17.5°C | 34.6°C | 11.8°C | 49 mm | 64% | 0.7 m/s | 5.5 |
| 1996 | 29.7°C | 23.9°C | 18.2°C | 32.2°C | 15.2°C | 86 mm | 71% | 0.6 m/s | 5.3 |
| 1995 | 33.6°C | 27.3°C | 20.9°C | 38.6°C | 17.6°C | 83 mm | 64% | 0.8 m/s | 5.1 |
| 1994 | 28.9°C | 23.4°C | 17.9°C | 32.8°C | 13.9°C | 106 mm | 74% | 0.7 m/s | 4.9 |
| 1993 | 32.0°C | 25.7°C | 19.5°C | 35.8°C | 15.6°C | 118 mm | 66% | 0.6 m/s | 5 |
| 1992 | 28.9°C | 23.1°C | 17.3°C | 32.4°C | 12.0°C | 114 mm | 72% | 0.6 m/s | 4.4 |
| 1991 | 28.9°C | 23.6°C | 18.3°C | 33.3°C | 14.4°C | 143 mm | 76% | 0.6 m/s | 5 |
| 1990 | 31.5°C | 25.3°C | 19.1°C | 35.9°C | 15.5°C | 109 mm | 65% | 0.7 m/s | 5.1 |
| 1989 ❄️ | 27.9°C | 22.9°C | 17.8°C | 30.4°C | 9.3°C | 107 mm | 79% | 0.6 m/s | 5.1 |
| 1988 | 32.7°C | 26.2°C | 19.7°C | 37.6°C | 14.2°C | 113 mm | 63% | 0.6 m/s | 4.7 |
| 1987 | 33.6°C | 26.8°C | 20.0°C | 36.6°C | 14.0°C | 61 mm | 59% | 0.7 m/s | 5 |
| 1986 | 30.6°C | 24.4°C | 18.2°C | 35.2°C | 7.7°C | 135 mm | 66% | 0.7 m/s | 4.7 |
| 1985 | 29.2°C | 23.7°C | 18.1°C | 34.5°C | 14.2°C | 134 mm | 71% | 0.7 m/s | 4.5 |
| 1984 | 28.7°C | 23.3°C | 18.0°C | 31.4°C | 12.5°C | 63 mm | 75% | 0.7 m/s | 4.7 |
| 1983 | 33.6°C | 26.9°C | 20.2°C | 40.0°C | 13.6°C | 85 mm | 60% | 0.7 m/s | — |
| 1982 | 29.6°C | 23.6°C | 17.7°C | 33.4°C | 12.4°C | 118 mm | 71% | 0.7 m/s | — |
| 1981 | 30.8°C | 24.4°C | 17.9°C | 34.6°C | 13.3°C | 88 mm | 66% | 0.7 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 30.9°C with lows near 18.9°C (mean 24.9°C), based on 45 years of NASA POWER data.
August averages 97 mm of rainfall in Knoxville, about average for rainfall. The wettest on record was 236 mm in 2021.
The hottest August reached 40°C in 1983. The coldest dipped to 7.7°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 0.6°C. Daytime highs moved from 30.4°C to 30.8°C and overnight lows from 18.4°C to 19.2°C over the same span.
August is one of the warmer months of the year in Knoxville and about average for rainfall, so plan for around 30.9°C daytime highs and 18.9°C at night.
Not quite — August is the 11th coolest month in Knoxville, averaging 24.9°C.
For August in Knoxville, pack light, breathable clothing and sun protection, with typical highs of 30.9°C and lows of 18.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 69% — moderately humid.
Average wind speed in August is 0.7 m/s. The windiest August on record averaged 0.8 m/s (1995).
The wettest August on record was 2021 with 236 mm. On average, August sees 97 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Knoxville behaves each August, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for August specifically, along with year-by-year records and how the month has changed over the decades.
