Knoxville, Tennessee climate: Normal weather by month, frost dates and records
Knoxville's normal year runs from 30°F January nights to 88°F July afternoons, with 51.9 inches of precipitation and 5 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 15.3°C, January lows of −1°C, July highs of 31°C, 1,319 mm of precipitation a year.
- NOAA stationKnoxville Airport
- Station IDUSW00013891
- Location35.82°N 83.99°W
- Elevation962 ft (293 m)
- From the center11 miles
- Population198,722
On October 14, the normal high in Knoxville is 73°F and the normal low 50°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Knoxville.
- Jan 48° 30°
- Feb 53° 33°
- Mar 61° 40°
- Apr 71° 48°
- May 79° 57°
- Jun 86° 65°
- Jul 88° 69°
- Aug 88° 68°
- Sep 83° 61°
- Oct 72° 49°
- Nov 60° 38°
- Dec 51° 33°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Knoxville each month?
July is the warmest month, with normal highs of 88°F; January the coldest, with normal lows of 30°F. The most precipitation falls in July (5.25 in), the least in October (2.81 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 48°F | 30°F | 39.1°F | 4.76 | 1.7 | 12 | <1 | 19 | 10 h |
| February | 53°F | 33°F | 42.9°F | 4.81 | 1.4 | 12 | <1 | 14 | 10 h 50 min |
| March | 61°F | 40°F | 50.6°F | 4.89 | 0.9 | 13 | <1 | 8 | 11 h 50 min |
| April | 71°F | 48°F | 59.6°F | 4.71 | 0.0 | 11 | <1 | 1 | 13 h |
| May | 79°F | 57°F | 67.9°F | 4.13 | 0.0 | 11 | 1 | <1 | 14 h |
| June | 86°F | 65°F | 75.3°F | 4.24 | 0.0 | 12 | 7 | <1 | 14 h 40 min |
| July | 88°F | 69°F | 78.5°F | 5.25 | 0.0 | 12 | 13 | <1 | 14 h 20 min |
| August | 88°F | 68°F | 77.6°F | 3.63 | 0.0 | 10 | 11 | <1 | 13 h 30 min |
| September | 83°F | 61°F | 71.8°F | 3.49 | 0.0 | 8 | 5 | <1 | 12 h 30 min |
| October | 72°F | 49°F | 60.3°F | 2.81 | 0.0 | 8 | <1 | 1 | 11 h 20 min |
| November | 60°F | 38°F | 49.0°F | 4.21 | 0.1 | 9 | <1 | 9 | 10 h 20 min |
| December | 51°F | 33°F | 41.9°F | 5.00 | 0.5 | 12 | <1 | 16 | 9 h 40 min |
| Year (annual) | 70°F | 49°F | 59.6°F | 51.93 | 4.6 | 129 | 37 | 67 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 9°C | −1°C | 3.9°C | 121 mm | 4 cm |
| February | 12°C | 1°C | 6.1°C | 122 mm | 4 cm |
| March | 16°C | 4°C | 10.3°C | 124 mm | 2 cm |
| April | 22°C | 9°C | 15.3°C | 120 mm | 0 cm |
| May | 26°C | 14°C | 19.9°C | 105 mm | 0 cm |
| June | 30°C | 18°C | 24.1°C | 108 mm | 0 cm |
| July | 31°C | 20°C | 25.8°C | 133 mm | 0 cm |
| August | 31°C | 20°C | 25.3°C | 92 mm | 0 cm |
| September | 28°C | 16°C | 22.1°C | 89 mm | 0 cm |
| October | 22°C | 9°C | 15.7°C | 71 mm | 0 cm |
| November | 16°C | 3°C | 9.4°C | 107 mm | 0 cm |
| December | 11°C | 0°C | 5.5°C | 127 mm | 1 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013891; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Knoxville?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, September has the fewest days with rain (8).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013891.
When is the last frost in Knoxville?
In Knoxville, the last spring frost (32°F) comes after April 1 in half of years and after April 17 in one year in ten; the first autumn frost comes before November 2 in half of years and before October 21 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 11 year in 10 after April 17; 9 in 10 after March 14
- First autumn frost, half of years before
- November 21 year in 10 before October 21; 9 in 10 before November 15
NOAA puts the median frost-free season at 215 days, and the season without a hard freeze (28°F) at 239 days.
A hard freeze (28°F) comes after March 19 in half of springs and before November 13 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Knoxville in zone 7b across its 14 ZIP code areas (7b in 37920, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Knoxville's NOAA station is in zone 7b: the coldest night of a typical year reaches 9°F (30 complete years).
Frost dates for every NOAA station in Tennessee · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00013891; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Knoxville ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Knoxville's 14 ZIP code areas are all in zone 7b. Each ZIP's frost dates are in the frost tool.
| ZIP code | Zone | Land in Knoxville |
|---|---|---|
| 37902 | 7b | 1.1 km² |
| 37909 | 7b | 17.6 km² |
| 37912 | 7b | 24.2 km² |
| 37914 | 7b | 27.3 km² |
| 37915 | 7b | 4.9 km² |
| 37916 | 7b | 3.6 km² |
| 37917 | 7b | 24.6 km² |
| 37918 | 7b | 24.0 km² |
| 37919 | 7b | 28.7 km² |
| 37920 | 7b | 37.8 km² |
| 37921 | 7b | 32.3 km² |
| 37922 | 7b | 8.0 km² |
| 37923 | 7b | 7.0 km² |
| 37924 | 7b | 9.6 km² |
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Knoxville?
In a normal year in Knoxville, 37 days a year reach 90°F, 67 nights fall to 32°F or colder and 129 days bring measurable precipitation.
- Days at 90°F or more
- 37a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 67a normal year
- Days that stay below freezing
- 5high of 32°F or less
- Days with 0.01 inch of precipitation
- 129a normal year
- Days with 1 inch of snow or more
- 2a normal year
The highest temperature in Knoxville's official record (kept by the National Weather Service since 1871) is 105°F, on June 30, 2012; the lowest is −24°F, on January 21, 1985.
The wettest calendar year on that record is 1875, with 73.77 in; the snowiest season is 1959–60, with 56.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00013891; records: ACIS (NOAA Regional Climate Centers), NWS threaded record TYSthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Knoxville, and how clear are its skies?
The summer (June-August) dew point averages 66°F. The muggiest month is July, with an average dew point of 68°F, above the 65°F at which most people call the air sticky; the driest air comes in January (29°F). February is the windiest month (7.3 mph on average), and September has the most clear or nearly clear hours (55%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 29°F | 66% | 51% | 6.8 mph | 39% | 40% |
| February | 34°F | 64% | 48% | 7.3 mph | 39% | 39% |
| March | 42°F | 61% | 45% | 7.3 mph | 42% | 32% |
| April | 51°F | 66% | 48% | 6.6 mph | 42% | 27% |
| May | 61°F | 71% | 52% | 5.7 mph | 38% | 22% |
| June | 66°F | 71% | 52% | 5.6 mph | 43% | 18% |
| July | 68°F | 74% | 54% | 4.9 mph | 43% | 16% |
| August | 65°F | 72% | 50% | 4.5 mph | 49% | 15% |
| September | 56°F | 73% | 50% | 4.8 mph | 55% | 19% |
| October | 44°F | 70% | 49% | 4.8 mph | 50% | 28% |
| November | 36°F | 71% | 54% | 5.8 mph | 44% | 36% |
| December | 31°F | 73% | 58% | 6.2 mph | 35% | 44% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00013891. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Knoxville?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Knoxville, 4.3 kWh per square metre a day. August is the sunniest month (77%) and February the cloudiest (65%). Among the 459 U.S. places of 50,000 or more, that ranks tied 352nd (with 32 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 69% | 2.5 |
| February | 65% | 3.0 |
| March | 69% | 4.1 |
| April | 73% | 5.3 |
| May | 74% | 5.8 |
| June | 76% | 6.1 |
| July | 75% | 5.8 |
| August | 77% | 5.4 |
| September | 76% | 4.7 |
| October | 76% | 3.8 |
| November | 76% | 2.9 |
| December | 68% | 2.2 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Knoxville need?
A normal year in Knoxville brings 3,528 heating degree days, 34% fewer than the median U.S. place (5,373), and 1,574 cooling degree days, 73% more than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 4,664 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 803 | 0 |
| February | 618 | 0 |
| March | 452 | 5 |
| April | 198 | 36 |
| May | 53 | 143 |
| June | 2 | 311 |
| July | 0 | 420 |
| August | 0 | 392 |
| September | 17 | 221 |
| October | 188 | 42 |
| November | 482 | 3 |
| December | 716 | 0 |
| Year (annual) | 3,528 | 1,574 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00013891. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Knoxville been warmer than normal lately?
2025 averaged 60.6°F, 1.0°F above the 1991-2020 normal of 59.6°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 60.3°F | +0.7°F | 46.54 | 1.4 |
| 2022 | 60.0°F | +0.4°F | 53.64 | 12.3 |
| 2023 | 61.3°F | +1.7°F | 47.51 | 0.0 |
| 2024 | 61.7°F | +2.1°F | 55.97 | 9.2 |
| 2025 | 60.6°F | +1.0°F | 46.75 | 6.9 |
Over 110 complete years from 1911 to 2025, the station's annual mean temperature rose at a fitted 1.0°F per century (+0.05°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00013891; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Knoxville's climate compare?
Knoxville is warmer than 90 of the other 115 places with their own NOAA record in Tennessee, and wetter than 16. Across the 7,247 U.S. stations with normals, its annual mean of 59.6°F is warmer than 74%.
In the Köppen classification computed from these normals, Knoxville is Cfa: temperate, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Knoxville share this climate record?
6 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Maryville, TN32,373 people · 5 mi S
- Alcoa, TN13,588 people · 1 mi E
- Eagleton Village, TN5,849 people · 3 mi SE
- Louisville, TN4,334 people · 4 mi W
- Wildwood, TN1,133 people · 7 mi E
- Rockford, TN841 people · 3 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Knoxville's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Knoxville. This page uses Knoxville Airport; the other differs by site and elevation, and the linked ones have pages of their own:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Knoxville Experiment Station USC00404946 | 5 mi S | 830 ft | 57.9°F | 26°F | 88°F | 55.8 | – | April 11 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Knoxville's climate
What is the coldest month in Knoxville?
January, with a normal high of 48°F and a normal low of 30°F. The warmest is July (88°F by day, 69°F at night).
Does it snow in Knoxville?
Yes: 5 inches in a normal year, falling on 4 days with 0.1 inch or more, the most in January (1.7 inches).
What is the rainiest month in Knoxville?
July, with 5.25 in of precipitation in a normal year; the driest is October with 2.81 in.
What plant hardiness zone is Knoxville in?
The USDA's 2023 map puts Knoxville in zone 7b across its 14 ZIP code areas (7b in 37920, the largest). By the same method at Knoxville's NOAA station, the coldest night of a typical year reaches 9°F (30 years, 1991-2020): zone 7b.
How late can frost come in Knoxville?
In half of years the last 32°F night comes after April 1; in one year in ten it comes after April 17. Waiting until April 17 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Knoxville in OctoberThis month day by day, its records and recent years
- Tennessee climateThe statewide normals and every place in the state
- Knoxville Experiment Station, TN6 miles from this station, 57.9°F a year
- Lenoir City, TN16 miles from this station, 59.1°F a year
- Townsend, TN19 miles from this station, 55.1°F a year
- Oak Ridge Atdd, TN19 miles from this station, 58.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made