What Growing Zone Is Montana In?
USDA hardiness zones
3b to 6a
2023 USDA Plant Hardiness Zone Map
Montana spans USDA hardiness zone 3b to 6a across its major population centers, according to the 2023 USDA Plant Hardiness Zone Map. That's a real range, not a single number: where you fall in it depends on where in the state you actually are.
Hardiness zone for ZIP 59101 (Billings)
Your USDA hardiness zone
Zone 5a
Avg. annual minimum (°F)
-20°F to -15°F
Avg. annual minimum (°C)
-29°C to -26°C
Nearest reference point: Billings, MT
This is a regional estimate based on the nearest of 826 reference points, each matched to the official 2023 USDA zone map. It’s accurate to within about a half-zone across most of the country, but elevation shifts zones over short distances, so if you’re in mountainous terrain, check the official USDA map for your exact address (see Sources below).
Montana's USDA Hardiness Zones
Here's how the zone shifts across Montana's major cities:
For your exact zone by ZIP code, use the Hardiness Zone Finder, and for what a zone number actually measures (and doesn't), see how zones actually work.
Frost Dates in Montana
Frost dates track zone, so they shift across Montana the same way the zone number does:
- West Yellowstone (zone 3): average last frost May 8 - May 22, average first frost Sep 8 - Sep 22.
- Missoula and Libby (zone 6): average last frost Mar 29 - Apr 12, average first frost Oct 18 - Nov 1.
These are averages, not guarantees. For your specific frost window, use the Frost Date Calculator. For a full vegetable-by-vegetable planting calendar already calculated from Montana's frost dates, see the Montana Planting Calendar.
Elevation drives an unusually wide zone range for one state: West Yellowstone sits at about 6,666 feet in a subarctic (Dfc) climate zone and lands in 3b, while Missoula at roughly 3,209 feet reaches 6a -- a 2.5-zone difference within the same state.
What Grows Well in Montana's Zones
A few real, zone-appropriate picks recommended by Montana State University Extension for Montana landscapes: not an exhaustive list, but a genuine starting point.
- Blanketflower (Gaillardia aristata)
- Narrowleaf purple coneflower (Echinacea angustifolia)
- Pasqueflower (Pulsatilla patens)
- Upright prairie coneflower (Ratibida columnifera)
- Blue giant hyssop (Agastache foeniculum)
- Penstemon (Penstemon spp.)
Ready to find your exact zone? Use the Hardiness Zone Finder: enter your ZIP code for a precise match against the 2023 USDA map.
Montana Growing Zone FAQ
What growing zone is Montana in?
Montana spans USDA hardiness zones 3b to 6a on the 2023 USDA Plant Hardiness Zone Map. West Yellowstone is zone 3b and Billings is zone 5a; enter your ZIP code in the Hardiness Zone Finder for your exact zone.
What growing zone is Billings, MT?
Billings is in USDA hardiness zone 5a on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
What growing zone is West Yellowstone, MT?
West Yellowstone is in USDA hardiness zone 3b on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
What growing zone is Helena, MT?
Helena is in USDA hardiness zone 5a on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
What growing zone is Missoula, MT?
Missoula is in USDA hardiness zone 6a on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
Free book · 23 pages, PDF
The Spacing & Planting Cheat Sheet
When to start, when to plant, how far apart.
Sources & further reading
Zone and city data checked against the official USDA Plant Hardiness Zone Map. Plant recommendations sourced from Montana State University Extension. Climate note sourced from Montana State University Extension, MontGuide MT202503AG. For more on how we build and verify reference data across this site, see our methodology page.
Growing zones in nearby states
Gardening near a state line? Zones don't stop at the border:
Or browse all 51 state growing-zone guides.