What Growing Zone Is Wyoming In?
USDA hardiness zones
4a to 5b
2023 USDA Plant Hardiness Zone Map
Wyoming spans USDA hardiness zone 4a to 5b 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.
Find your exact zone
Your USDA hardiness zone
Zone 6b
Avg. annual minimum (°F)
-5°F to 0°F
Avg. annual minimum (°C)
-21°C to -18°C
Nearest reference point: Chicago, IL
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).
Wyoming's USDA Hardiness Zones
Here's how the zone shifts across Wyoming'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 Wyoming
Frost dates track zone, so they shift across Wyoming the same way the zone number does:
- Laramie and Jackson Hole (zone 4): average last frost Apr 23 - May 7, average first frost Sep 23 - Oct 7.
- Cheyenne and Casper (zone 5): average last frost Apr 8 - Apr 22, average first frost Oct 8 - Oct 22.
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 Wyoming's frost dates, see the Wyoming Planting Calendar.
University of Wyoming Extension's B-1090R notes that hardiness and adaptability of woody plant species is closely tied to altitude, and rates each recommended species with a maximum recommended elevation for reliable performance.
What Grows Well in Wyoming's Zones
A few real, zone-appropriate picks recommended by University of Wyoming Extension, B-1090R for Wyoming landscapes: not an exhaustive list, but a genuine starting point.
- Rocky Mountain juniper 'Wichita Blue' (Juniperus scopulorum 'Wichita Blue')
- Bristlecone pine (Pinus aristata)
- Wood's rose (Rosa woodsii)
- Silver buffaloberry (Shepherdia argentea)
- Wax currant (Ribes cereum)
- Little bluestem (Schizachyrium scoparium)
Ready to find your exact zone? Use the Hardiness Zone Finder: enter your ZIP code for a precise match against the 2023 USDA map.
Wyoming Growing Zone FAQ
What growing zone is Wyoming in?
Wyoming spans USDA hardiness zones 4a to 5b on the 2023 USDA Plant Hardiness Zone Map. Laramie is zone 4a and Jackson is zone 4b; enter your ZIP code in the Hardiness Zone Finder for your exact zone.
What growing zone is Laramie, WY?
Laramie is in USDA hardiness zone 4a 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 Jackson, WY?
Jackson is in USDA hardiness zone 4b 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 Casper, WY?
Casper 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 Cheyenne, WY?
Cheyenne is in USDA hardiness zone 5b on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
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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 University of Wyoming Extension, B-1090R. Climate note sourced from University of Wyoming Extension, B-1090R. 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:
- Colorado growing zones
- Utah growing zones
- Nebraska growing zones
- Idaho growing zones
- Montana growing zones
- South Dakota growing zones
Or browse all 51 state growing-zone guides.