Last frost date in Bozeman, MT
The average last frost in Bozeman is May 26. By June 14 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about September 22, which leaves 116 frost-free days. An early freeze before September 5 happens one year in ten.
- Safe after (10% risk)
- Jun 14
- Average first frost
- Sep 22
- Frost-free season
- 116 days
- Hard freeze (28°F) ends
- May 8
Hard freeze likely Fri night, low 25°F
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2244°
- FriOct 2325°hard freeze
- SatOct 2424°hard freeze
- SunOct 2525°hard freeze
- MonOct 2627°hard freeze
- TueOct 2727°hard freeze
- WedOct 2827°hard freeze
Planting calendar for Bozeman
Windows count forward or back from the average frost dates above. Click a crop for dates across Montana.
TomatoesJun 2–Jun 16
PumpkinsJun 9–Jun 23
SunflowersMay 26–Jun 16
CucumbersJun 9–Jun 16
CornJun 2–Jun 16
Sweet potatoesJun 16–Jun 30
WatermelonJun 9–Jun 23
Green beansJun 2–Jun 23
ZucchiniJun 2–Jun 16
OkraJun 16–Jun 30
PeppersJun 9–Jun 23
BasilJun 2–Jun 16
Butternut squashJun 2–Jun 16
CantaloupeJun 9–Jun 23
EggplantJun 9–Jun 23
PotatoesApr 28–May 12
OnionsApr 14–May 5
CarrotsMay 5–Jun 9
LettuceMay 12–Jun 2
BroccoliApr 28–May 12
BeetsApr 28–Jun 9
PeasApr 14–Apr 28
CabbageApr 28–May 12
RadishesApr 21–Jun 2
Brussels sproutsMay 12–May 26
SpinachApr 14–May 5
CilantroMay 12–Jun 2
KaleApr 28–May 12
Collard greensApr 28–May 12
TurnipsApr 28–May 12
DillMay 26–Jun 9
CeleryJun 2–Jun 9
CauliflowerMay 12–May 26
LeeksMay 12–May 26
Swiss chardMay 12–Jun 9
ParsleyMay 12–Jun 2
Tulip bulbsSep 8–Oct 13
GarlicSep 1–Oct 6
Daffodil bulbsAug 25–Oct 6
StrawberriesApr 28–May 12
AsparagusApr 28–May 12The frost-free season here is short for pumpkins, sweet potatoes, butternut squash. 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 9 | May 26 | Jun 14 | Sep 5 | Sep 22 | Oct 5 |
| Hard freeze, 28°F | Apr 23 | May 8 | May 26 | Sep 18 | Oct 3 | Oct 19 |
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 Bozeman Montana State University (USC00241044) sits 1.5 miles from the center of Bozeman at 4,913 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 Bozeman, MT?
The average last frost date in Bozeman is May 26, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after June 14.
When is the first frost in Bozeman?
The first frost in fall usually comes around September 22. One year in ten it arrives before September 5.
How long is the growing season in Bozeman?
About 116 days between the average last and first frost.
When should I plant tomatoes in Bozeman?
Plant tomato seedlings outside from June 2 to June 16. Start seeds indoors six to eight weeks earlier.
Nearby in Montana
- HelenaMay 9
- Butte-Silver BowJun 13
- BillingsMay 4
- Great FallsMay 6
- MissoulaMay 10
- KalispellMay 31