Last frost date in Butte-Silver Bow (balance), Montana
June 13
Average last frost in spring. In an early year (1 in 10) it's over by May 27; in a late year (1 in 10) it comes after July 1.
September 5
Average first frost in fall. 1 year in 10 it comes by August 24.
Source: NOAA U.S. Climate Normals 1991–2020, station Butte Bert Mooney AP (USW00024135), 9 miles from Butte-Silver Bow (balance), elevation 5,506 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | May 27 | June 13 | July 1 |
| First frost in fall | Aug 24 | Sept 5 | Sept 19 |
An early or late year is one in 10: 1 year in 10 the frost comes before the early date, and 1 year in 10 after the late date.
Frost-free days in an average year: 83
Planting calendar for Butte-Silver Bow (balance)
Fall planting
USDA dates for places whose average first freeze is about September 10 (Butte-Silver Bow (balance): September 5).
- Broccoli plantsMay 1 – June 1 (past for this year)
- Brussels sprouts plantsMay 1 – June 1 (past for this year)
- Cabbage plantsMay 1 – June 1 (past for this year)
- Cauliflower plantsMay 1 – July 1 (past for this year)
- Chervil and chivesMay 1 – June 15 (past for this year)
- Garden peasMay 1 – July 1 (past for this year)
- LeeksMay 1 – June 1 (past for this year)
- Onion plants plantsMay 1 – June 10 (past for this year)
- Onion seedMay 1 – June 10 (past for this year)
- Onion setsMay 1 – June 10 (past for this year)
- ParsleyMay 1 – June 15 (past for this year)
- ParsnipsMay 1 – June 15 (past for this year)
- PotatoesMay 1 – June 15 (past for this year)
- RadishesMay 1 – Aug 1 (past for this year)
- RutabagaMay 1 – June 15 (past for this year)
- SorrelMay 1 – June 15 (past for this year)
- SalsifyMay 10 – June 10 (past for this year)
- BeetsMay 15 – June 15 (past for this year)
- CarrotsMay 15 – June 15 (past for this year)
- Celery and celeriac plantsMay 15 – June 15 (past for this year)
- Chinese cabbageMay 15 – June 15 (past for this year)
- Collards plantsMay 15 – June 15 (past for this year)
- Corn saladMay 15 – July 1 (past for this year)
- Florence fennelMay 15 – July 15 (past for this year)
- Head lettuce plantsMay 15 – July 1 (past for this year)
- KaleMay 15 – June 15 (past for this year)
- Leaf lettuceMay 15 – July 15 (past for this year)
- Mustard greensMay 15 – July 15 (past for this year)
- Snap beansMay 15 – June 15 (past for this year)
- Swiss chardMay 15 – July 1 (past for this year)
- Upland cressMay 15 – July 1 (past for this year)
- Witloof chicoryMay 15 – June 15 (past for this year)
- DandelionJune 1 – July 1 (past for this year)
- EndiveJune 1 – July 1 (past for this year)
- KohlrabiJune 1 – July 1 (past for this year)
- SpinachJune 1 – July 15 (past for this year)
- Summer squashJune 1 – 20 (past for this year)
- TurnipsJune 1 – July 1 (past for this year)
- TomatoesJune 10 – 20 (past for this year)
- Rhubarb plantsSept 15 – Oct 15 (past for this year)
USDA lists garlic, horseradish, shallots as generally spring-planted here.
Spring planting
USDA dates for places whose average last freeze is about June 10 (Butte-Silver Bow (balance): June 13).
- DandelionMay 1 – 30
- LeeksMay 1 – 15
- SpinachMay 1 – June 15
- Garden peasMay 10 – June 15
- Onion plants plantsMay 10 – June 10
- Onion seedMay 10 – June 10
- Onion setsMay 10 – June 10
- ShallotsMay 10 – June 1
- Asparagus plantsMay 15 – June 1
- BeetsMay 15 – June 15
- Chervil and chivesMay 15 – June 1
- Corn saladMay 15 – June 15
- EndiveMay 15 – June 1
- Florence fennelMay 15 – June 1
- GarlicMay 15 – June 1
- Horseradish plantsMay 15 – June 1
- KaleMay 15 – June 1
- KohlrabiMay 15 – June 1
- PotatoesMay 15 – June 1
- RadishesMay 15 – June 1
- Rhubarb plantsMay 15 – June 1
- TurnipsMay 15 – June 15
- Upland cressMay 15 – June 15
- Broccoli plantsMay 20 – June 10
- Brussels sprouts plantsMay 20 – June 10
- Cabbage plantsMay 20 – June 1
- CarrotsMay 20 – June 1
- Chinese cabbageMay 20 – June 1
- Collards plantsMay 20 – June 1
- Head lettuce plantsMay 20 – June 30
- Leaf lettuceMay 20 – June 30
- Mustard greensMay 20 – June 30
- ParsleyMay 20 – June 10
- ParsnipsMay 20 – June 10
- RutabagaMay 20 – June 1
- SalsifyMay 20 – June 1
- SorrelMay 20 – June 10
- Cauliflower plantsJune 1 – 15
- Celery and celeriac plantsJune 1 – 15
- Swiss chardJune 1 – 15
- Witloof chicoryJune 1 – 15
- Summer squashJune 10 – 20
- TomatoesJune 15 – 30
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5 (earliest safe spring and latest safe fall dates), applied to this place's NOAA frost dates. “Plants” means setting out transplants, not sowing seed. How we match the table.
Nearby in Montana
- Helena 57 mi · last frost May 9
- Belgrade 72 mi · last frost May 26
- Bozeman 79 mi · last frost May 26
- Missoula 94 mi · last frost May 10
- Great Falls 128 mi · last frost May 6