Knoxville, Tennessee Weather
Thunder quiets the land. Day 93 of summer. Read this microseason across nine climate regions →
Knoxville weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 10:15 AM EDT · Open-Meteo
- TodaySep 21Heavy Showers later21%1.0″93°71°—
- TuesdaySep 22Overcast41%1.1″84°70°-9°
- WednesdaySep 23Showers69%—86°65°+2°
- ThursdaySep 24Showers52%—75°64°-11°
- FridaySep 25Overcast——79°59°+4°
- SaturdaySep 26Overcast——80°57°+1°
- SundaySep 27Overcast——72°63°-8°
Air quality now AQI 56 · Moderate
AQI 56 (Moderate), driven by PM2.5. AQI projected to climb to 91 over the next 6 hours. PM2.5 at 9.6 µg/m³ (AQI 52) with a 0.96 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in stagnant air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 7 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 45 now. With UV 3.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 14.
- Present
- AQI 45
- UV peak
- 3.3 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 14
PM × Wind × Precip
PM2.5 at 9.6 µg/m³ (AQI 52) with a 0.96 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.96
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
September dries up ditches or breaks down bridges.
- Moonrise
- 4:56 PM
- Moonset
- 2:08 AM
- In sign
- ♑︎ Capricorn
Thunder quiets the land
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Knoxville at a glance
- Today vs. normal: Today averages 82°F (high 93°F, low 71°F), 13°F above the 69°F normal for Sep 21
- Last frost: April 11 (1991–2020 median, NOAA station 8 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash
16-Day Forecast — Knoxville
- Mon93°71°21%
- Tue84°70°41%
- Wed86°65°69%
- Thu75°64°52%
- Fri79°59°6%
- Sat80°57°2%
- Sun72°63°4%
- Mon80°61°7%
- Tue84°63°11%
- Wed84°65°22%
- Thu86°66°15%
- Fri86°63°23%
- Sat88°65°21%
- Sun72°65°13%
- Mon67°54°35%
- Tue66°47°29%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Knoxville
Interactive wind and temperature map centered on Knoxville — it loads in your browser. Open the full weather map.
Right now in the garden
Fall planting + final harvests
As of September 21, the season's first frost (typically October 28) is approaching. Pick what frost-tender plants still carry before the next cold front. This city's planting calendar for September: plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, and winter squash.
SPC Convective Outlook
Storm Prediction Center — Knoxville
SPC has placed Knoxville in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook.
Sun & seasons in Knoxville
Knoxville sits in Knox County, where the year’s longest day runs 14h 36m of daylight and its shortest just 9h 43m — a swing of +4h 53m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Nashville, the state’s largest city, lies about 159 miles to the W. The nearest town Knoxville tracks is Kahite, roughly 32 miles to the SSW.
Air quality in Knoxville
Air quality in Knoxville’s county has held roughly steady since 2020; its cleanest year on record was 2020 (median AQI 44). See the full air-quality history for Knoxville.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| March | lettuce, peas, spinach, radishes | — |
| April | lettuce, peas, spinach, radishes | spinach, radishes |
| May | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, spinach, beans, summer squash |
| July | tomatoes, peppers, beans, squash | tomatoes, peppers, beans, summer squash, garlic |
| August | beans, squash, fall brassicas, carrots | tomatoes, peppers, beans, summer squash, winter squash |
| September | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| October | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
| November | — | fall brassicas, carrots |
A year in weather
Knoxville peaks at about 77°F in July and bottoms near 37°F in January; December brings the heaviest rain (4.9 inches) and October the least (2.4 inches).
| Month | Mean temp | Precip |
|---|---|---|
| January | 37° | 4.6″ |
| February | 40° | 4.1″ |
| March | 48° | 4.8″ |
| April | 57° | 4.0″ |
| May | 65° | 3.5″ |
| June | 74° | 3.8″ |
| July | 77° | 4.5″ |
| August | 76° | 4.4″ |
| September | 71° | 2.7″ |
| October | 60° | 2.4″ |
| November | 48° | 3.7″ |
| December | 40° | 4.9″ |
Regional context
Similar climates Powell, TN, Halls, TN, John Sevier, TN
In Knoxville, modelled 1991-2020 normals (EC_Earth3P_HR model via Open-Meteo) put January near 37°F and July near 77°F — a 41°F seasonal arc — with about 47.5 inches of precipitation.
Rainfall in Knoxville splits evenly between the seasons: December tops out at 4.9 inches, and October logs 2.4 inches — neither half of Knoxville's year dominates. That even rhythm groups Knoxville with places like Powell, TN, Halls, TN and John Sevier, TN.
Once Knoxville passes April 11, freezes fade and Knoxville's beds take peas, lettuce, spinach, and radishes. Knoxville's heat-lovers — tomatoes, peppers, squash — hold off until Knoxville's frost risk clears, 10-14 days on. Frost returns to Knoxville near October 28, ending the tender-crop season. That date is a median: Knoxville freezes sooner in half of years.
Similar climates: Powell, TN, Halls, TN, John Sevier, TN, Karns, TN, Rockford, TN.
Frequently asked
- When does it freeze in Knoxville?
- Knoxville's last spring frost lands near April 11, and in Knoxville the first fall frost follows around October 28.
- What is the rainy season in Knoxville?
- Knoxville sees its heaviest rain in December (around 4.9 inches), part of roughly 48 inches a year.
- What is the warmest month in Knoxville?
- July is Knoxville's warmest month, averaging about 77°F.
- What is the coldest month in Knoxville?
- Knoxville bottoms out in January, with a mean near 37°F.
- When can I start a vegetable garden in Knoxville?
- Time tomatoes in Knoxville for two weeks after April 11; peas and greens start at Knoxville's frost line.
- What hardiness zone is Knoxville?
- Knoxville's USDA zone comes from its January mean (37°F); enter the ZIP on the USDA lookup for the number.
- What is the 10-day forecast for Knoxville?
- Knoxville's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Knoxville?
- See this week's day-by-day rain chances for Knoxville in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Knoxville?
- Current conditions for Knoxville and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Knoxville forecast updated?
- The Knoxville forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Knoxville?
- Today's sunrise and sunset times for Knoxville are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Knoxville?
- The next few days in Knoxville's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Knoxville sits at 36.0°N; its climate zone is humid subtropical (Köppen approximation).
ZIP codes in Knoxville
- 37901
- 37902
- 37909
- 37912
- 37914
- 37915
- 37916
- 37917
- 37918
- 37919
- 37920
- 37921
- 37922
- 37923
- 37924
- 37927
- 37928
- 37929
- 37931
- 37932
- 37938
- 37939
- 37950
- 37995
- 37996
- 37997