Last frost date in Post Falls, ID

Average last frost
April 22

Expect the last frost in Post Falls around April 22. Frost after May 6 happens in only one year out of ten. The first fall frost usually arrives about October 18, which leaves 179 frost-free days. An early freeze before October 4 happens one year in ten.

Safe after (10% risk)
May 6
Average first frost
Oct 18
Frost-free season
179 days
Hard freeze (28°F) ends
Apr 1
Next 6 nights in Post Falls

Frost likely Fri night, low 32°F

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

  1. ThuOct 2244°
  2. FriOct 2332°frost
  3. SatOct 2435°possible frost
  4. SunOct 2533°possible frost
  5. MonOct 2632°frost
  6. TueOct 2732°frost
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Apr 22First frost Oct 18179 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND179 frost-free days
Frost risk through the year at Coeur D'alene, 7.5 miles from Post Falls.

Planting calendar for Post Falls

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 29–May 13
PumpkinsMay 6–May 20
SunflowersApr 22–May 13
CucumbersMay 6–May 13
CornApr 29–May 13
Sweet potatoesMay 13–May 27
WatermelonMay 6–May 20
Green beansApr 29–May 20
ZucchiniApr 29–May 13
OkraMay 13–May 27
PeppersMay 6–May 20
BasilApr 29–May 13
Butternut squashApr 29–May 13
CantaloupeMay 6–May 20
EggplantMay 6–May 20
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesMar 25–Apr 8
OnionsMar 11–Apr 1
CarrotsApr 1–May 6
LettuceApr 8–Apr 29
BroccoliMar 25–Apr 8
BeetsMar 25–May 6
PeasMar 11–Mar 25
CabbageMar 25–Apr 8
RadishesMar 18–Apr 29
Brussels sproutsApr 8–Apr 22
SpinachMar 11–Apr 1
CilantroApr 8–Apr 29
KaleMar 25–Apr 8
Collard greensMar 25–Apr 8
TurnipsMar 25–Apr 8
DillApr 22–May 6
CeleryApr 29–May 6
CauliflowerApr 8–Apr 22
LeeksApr 8–Apr 22
Swiss chardApr 8–May 6
ParsleyApr 8–Apr 29
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsOct 4–Nov 8
GarlicSep 27–Nov 1
Daffodil bulbsSep 20–Nov 1
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesMar 25–Apr 8
AsparagusMar 25–Apr 8

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FApr 4Apr 22May 6Oct 4Oct 18Nov 5
Hard freeze, 28°FMar 13Apr 1Apr 21Oct 15Nov 1Nov 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 Coeur D'alene (USC00101956) sits 7.5 miles from the center of Post Falls at 2,133 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 Post Falls, ID?

The average last frost date in Post Falls is April 22, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 6.

When is the first frost in Post Falls?

The first frost in fall usually comes around October 18. One year in ten it arrives before October 4.

How long is the growing season in Post Falls?

About 179 days between the average last and first frost.

When should I plant tomatoes in Post Falls?

Plant tomato seedlings outside from April 29 to May 13. Start seeds indoors six to eight weeks earlier.

Nearby in Idaho

All 16 cities in Idaho