Last frost date in Lewiston, ID

Average last frost
April 6

The average last frost in Lewiston is April 6. By April 26 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about October 26, which leaves 200 frost-free days. An early freeze before October 10 happens one year in ten.

Safe after (10% risk)
Apr 26
Average first frost
Oct 26
Frost-free season
200 days
Hard freeze (28°F) ends
Mar 15
Next 6 nights in Lewiston

Frost possible in low spots Fri night, low 35°F

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

  1. ThuOct 2247°
  2. FriOct 2335°possible frost
  3. SatOct 2437°
  4. SunOct 2538°
  5. MonOct 2637°
  6. TueOct 2737°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 6First frost Oct 26200 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND200 frost-free days
Frost risk through the year at Lewiston Nez Perce County Airport, 1.7 miles from Lewiston.

Planting calendar for Lewiston

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

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesApr 13–Apr 27
PumpkinsApr 20–May 4
SunflowersApr 6–Apr 27
CucumbersApr 20–Apr 27
CornApr 13–Apr 27
Sweet potatoesApr 27–May 11
WatermelonApr 20–May 4
Green beansApr 13–May 4
ZucchiniApr 13–Apr 27
OkraApr 27–May 11
PeppersApr 20–May 4
BasilApr 13–Apr 27
Butternut squashApr 13–Apr 27
CantaloupeApr 20–May 4
EggplantApr 20–May 4
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 9–Mar 23
OnionsFeb 23–Mar 16
CarrotsMar 16–Apr 20
LettuceMar 23–Apr 13
BroccoliMar 9–Mar 23
BeetsMar 9–Apr 20
PeasFeb 23–Mar 9
CabbageMar 9–Mar 23
RadishesMar 2–Apr 13
Brussels sproutsMar 23–Apr 6
SpinachFeb 23–Mar 16
CilantroMar 23–Apr 13
KaleMar 9–Mar 23
Collard greensMar 9–Mar 23
TurnipsMar 9–Mar 23
DillApr 6–Apr 20
CeleryApr 13–Apr 20
CauliflowerMar 23–Apr 6
LeeksMar 23–Apr 6
Swiss chardMar 23–Apr 20
ParsleyMar 23–Apr 13
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 12–Nov 16
GarlicOct 5–Nov 9
Daffodil bulbsSep 28–Nov 9
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 9–Mar 23
AsparagusMar 9–Mar 23

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FMar 20Apr 6Apr 26Oct 10Oct 26Nov 12
Hard freeze, 28°FFeb 25Mar 15Apr 4Oct 20Nov 8Nov 28

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 Lewiston Nez Perce County Airport (USW00024149) sits 1.7 miles from the center of Lewiston at 1,436 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 Lewiston, ID?

The average last frost date in Lewiston is April 6, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 26.

When is the first frost in Lewiston?

The first frost in fall usually comes around October 26. One year in ten it arrives before October 10.

How long is the growing season in Lewiston?

About 200 days between the average last and first frost.

When should I plant tomatoes in Lewiston?

Plant tomato seedlings outside from April 13 to April 27. Start seeds indoors six to eight weeks earlier.

Nearby in Idaho

All 16 cities in Idaho