USDA hardiness zone lookup
Butte, MT — USDA Zone 4a
Butte, Montana · 91-day growing season
Frost dates and growing season in Butte
| USDA hardiness zone | Zone 4a |
|---|---|
| Average last spring frost | June 8 |
| Average first fall frost | September 7 |
| Growing season length | ~91 days |
| Temperature range (F) | -30 to -20°F |
| Temperature range (C) | -34 to -29°C |
All of Butte's mapped ZIP codes fall in the same hardiness band, Zone 4a.
These are 50%-probability averages modeled from Butte's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by June 8, but a colder-than-average year can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.
Growing season in Butte
Butte, Montana sits in USDA Zone 4a, with roughly 91 frost-free days between an average last spring frost around June 8 and a first fall frost around September 7. That is a short season — start warm-season crops indoors 6-8 weeks early and lean on quick-maturing, cold-tolerant cultivars to beat the first fall frost.
What grows in Butte
Butte falls in USDA Zone 4a, so the same hardiness constraints apply as the full Zone 4 guide. Vegetables, herbs, and fruit trees rated to Zone 4a (or hardier) will overwinter here in a typical year.
- Apple, pear, plum, sour cherry
- Blueberries (highbush)
- Raspberries
- Strawberries
- Tomatoes
- Peppers (short-season)
- Cucumbers
- Beans
- Squash (summer + winter)
- Garlic
What to plant in Butte this week
Butte's last frost is around June 8. This is the spring transplant window — start tomatoes and peppers indoors if you haven't, and direct-sow cold-tolerant crops now.
- When to plant tomatoes in zone 4
- When to plant peppers in zone 4
- When to plant basil in zone 4
- When to plant bush beans in zone 4
- When to plant cucumbers in zone 4
Full planting calendar for Butte
Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 4 averages:
- When to plant tomatoes in zone 4
- When to plant peppers in zone 4
- When to plant basil in zone 4
- When to plant garlic in zone 4
- When to plant lettuce in zone 4
- When to plant bush beans in zone 4
- When to plant cucumbers in zone 4
- When to plant summer squash in zone 4
- When to plant peas in zone 4
- When to plant carrots in zone 4
ZIP codes in Butte
Drill down to the precise frost window and planting calendar for a specific ZIP in Butte:
Local microclimate notes
Zone tables give you the average — but Buttegardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record — the last time you actually got frost damage — beats any national average.
Source and methodology
Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from Butte's USDA hardiness zone and regional NOAA 1991-2020 climate normals — zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations draw on US Cooperative Extension references, curated by the Growli editorial team. Last reviewed June 2026.
Other cities in Montana
- Billings, MT — USDA Zone 5a
- Bozeman, MT — USDA Zone 4b
- Great Falls, MT — USDA Zone 4b
- Helena, MT — USDA Zone 5a
- Kalispell, MT — USDA Zone 5a
- Livingston, MT — USDA Zone 4b
- Missoula, MT — USDA Zone 5b
- All of Montana by zone