Last frost date in Knoxville, TN

Average last frost
April 11

In Knoxville, the last spring frost comes around April 11 in an average year. Wait until April 29 if you want 90% odds of no more frost. The first fall frost usually arrives about October 28, which leaves 198 frost-free days. An early freeze before October 13 happens one year in ten.

Safe after (10% risk)
Apr 29
Average first frost
Oct 28
Frost-free season
198 days
Hard freeze (28°F) ends
Mar 31
Next 7 nights in Knoxville

No frost in the next 7 nights

National Weather Service forecast, updated Oct 22, 12:57 UTC

  1. ThuOct 2243°
  2. FriOct 2342°
  3. SatOct 2444°
  4. SunOct 2543°
  5. MonOct 2645°
  6. TueOct 2748°
  7. WedOct 2847°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 11First frost Oct 28198 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND198 frost-free days
Frost risk through the year at Knoxville Experiment Station, 5.0 miles from Knoxville.

Planting calendar for Knoxville

Windows count forward or back from the average frost dates above. Click a crop for dates across Tennessee.

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesApr 18–May 2
PumpkinsApr 25–May 9
SunflowersApr 11–May 2
CucumbersApr 25–May 2
CornApr 18–May 2
Sweet potatoesMay 2–May 16
WatermelonApr 25–May 9
Green beansApr 18–May 9
ZucchiniApr 18–May 2
OkraMay 2–May 16
PeppersApr 25–May 9
BasilApr 18–May 2
Butternut squashApr 18–May 2
CantaloupeApr 25–May 9
EggplantApr 25–May 9
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 14–Mar 28
OnionsFeb 28–Mar 21
CarrotsMar 21–Apr 25
LettuceMar 28–Apr 18
BroccoliMar 14–Mar 28
BeetsMar 14–Apr 25
PeasFeb 28–Mar 14
CabbageMar 14–Mar 28
RadishesMar 7–Apr 18
Brussels sproutsMar 28–Apr 11
SpinachFeb 28–Mar 21
CilantroMar 28–Apr 18
KaleMar 14–Mar 28
Collard greensMar 14–Mar 28
TurnipsMar 14–Mar 28
DillApr 11–Apr 25
CeleryApr 18–Apr 25
CauliflowerMar 28–Apr 11
LeeksMar 28–Apr 11
Swiss chardMar 28–Apr 25
ParsleyMar 28–Apr 18
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 14–Nov 18
GarlicOct 7–Nov 11
Daffodil bulbsSep 30–Nov 11
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 14–Mar 28
AsparagusMar 14–Mar 28

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FMar 26Apr 11Apr 29Oct 13Oct 28Nov 9
Hard freeze, 28°FMar 13Mar 31Apr 16Oct 24Nov 6Nov 20

Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.

Where these numbers come from

NOAA station Knoxville Experiment Station (USC00404946) sits 5.0 miles from the center of Knoxville at 830 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.

Questions

When is the last frost in Knoxville, TN?

The average last frost date in Knoxville is April 11, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 29.

When is the first frost in Knoxville?

The first frost in fall usually comes around October 28. One year in ten it arrives before October 13.

How long is the growing season in Knoxville?

About 198 days between the average last and first frost.

When should I plant tomatoes in Knoxville?

Plant tomato seedlings outside from April 18 to May 2. Start seeds indoors six to eight weeks earlier.

Nearby in Tennessee

All 33 cities in Tennessee