Last frost date in Kalispell, MT
Expect the last frost in Kalispell around May 31. Frost after June 22 happens in only one year out of ten. The first fall frost usually arrives about September 10, which leaves 100 frost-free days. An early freeze before August 26 happens one year in ten.
- Safe after (10% risk)
- Jun 22
- Average first frost
- Sep 10
- Frost-free season
- 100 days
- Hard freeze (28°F) ends
- May 10
Hard freeze likely Fri night, low 28°F
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2240°
- FriOct 2328°hard freeze
- SatOct 2427°hard freeze
- SunOct 2523°hard freeze
- MonOct 2625°hard freeze
- TueOct 2725°hard freeze
- WedOct 2824°hard freeze
Planting calendar for Kalispell
Windows count forward or back from the average frost dates above. Click a crop for dates across Montana.
TomatoesJun 7–Jun 21
PumpkinsJun 14–Jun 28
SunflowersMay 31–Jun 21
CucumbersJun 14–Jun 21
CornJun 7–Jun 21
Sweet potatoesJun 21–Jul 5
WatermelonJun 14–Jun 28
Green beansJun 7–Jun 28
ZucchiniJun 7–Jun 21
OkraJun 21–Jul 5
PeppersJun 14–Jun 28
BasilJun 7–Jun 21
Butternut squashJun 7–Jun 21
CantaloupeJun 14–Jun 28
EggplantJun 14–Jun 28
PotatoesMay 3–May 17
OnionsApr 19–May 10
CarrotsMay 10–Jun 14
LettuceMay 17–Jun 7
BroccoliMay 3–May 17
BeetsMay 3–Jun 14
PeasApr 19–May 3
CabbageMay 3–May 17
RadishesApr 26–Jun 7
Brussels sproutsMay 17–May 31
SpinachApr 19–May 10
CilantroMay 17–Jun 7
KaleMay 3–May 17
Collard greensMay 3–May 17
TurnipsMay 3–May 17
DillMay 31–Jun 14
CeleryJun 7–Jun 14
CauliflowerMay 17–May 31
LeeksMay 17–May 31
Swiss chardMay 17–Jun 14
ParsleyMay 17–Jun 7
Tulip bulbsAug 27–Oct 1
GarlicAug 20–Sep 24
Daffodil bulbsAug 13–Sep 24
StrawberriesMay 3–May 17
AsparagusMay 3–May 17The frost-free season here is short for pumpkins, sunflowers, corn, sweet potatoes, watermelon, peppers, butternut squash, cantaloupe. Start them indoors and look for early varieties.
Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | May 13 | May 31 | Jun 22 | Aug 26 | Sep 10 | Sep 25 |
| Hard freeze, 28°F | Apr 28 | May 10 | May 26 | Sep 9 | Sep 27 | Oct 7 |
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 Kalispell Glacier Airport (USC00244558) sits 6.8 miles from the center of Kalispell at 2,957 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 Kalispell, MT?
The average last frost date in Kalispell is May 31, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after June 22.
When is the first frost in Kalispell?
The first frost in fall usually comes around September 10. One year in ten it arrives before August 26.
How long is the growing season in Kalispell?
About 100 days between the average last and first frost.
When should I plant tomatoes in Kalispell?
Plant tomato seedlings outside from June 7 to June 21. Start seeds indoors six to eight weeks earlier.
Nearby in Montana
- MissoulaMay 10
- Great FallsMay 6
- HelenaMay 9
- Butte-Silver BowJun 13
- BozemanMay 26
- BillingsMay 4