Kemmerer, Wyoming, sits in USDA hardiness zones 5a-6b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
A short list that earns its place here — potato, indian paintbrush, cottonwood, and rhubarb — with any one site's soil, sun, and drainage making the final cut.
Even in Kemmerer, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Kemmerer lot. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
5a-6b
Last Hard Freeze (28°F)
May 14
Town normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Sep 26
Town normal — light frosts arrive a few weeks earlier
City Area
5K acres
Hardiness Zone Range
Zone maps are averages across Kemmerer. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil varies lot by lot — soil types explained.
What Grows in Kemmerer
Plants matched to Kemmerer's USDA zones 5a-6b — each links to its full growing profile.



Is it too late to plant in Kemmerer?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 26 — long-season crops need about 90 days of runway, quick greens only 30. Even here the calendar’s edges hold value: thirty-day greens late in the window, then garlic and a rested bed for spring.

Growing Challenges in Wyoming
What an experienced grower plans around here — each one has a move.

Extremely short growing season (60-90 frost-free days)
At 60-90 frost-free days, a greenhouse or high tunnel isn't optional equipment — it's where the season actually happens.

Very low rainfall requires irrigation
Drip irrigation under mulch makes scarce water go the distance — build the system before the first bed.

Persistent high winds desiccate and damage plants
Windbreaks first, plants second — a sheltered bed loses a fraction of the moisture an exposed one does.
For cultivar selection, pest pressure, and planting-time guidance specific to Wyoming, the University of Wyoming Extension is the authoritative local source.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Total Sites
84
within ~10 miles of Kemmerer
Risk Level
Moderate
Highest-severity
4 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Kemmerer
Severity Distribution
within ~10 miles of Kemmerer
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Kemmerer, Nitrate runs higher than the national average — 28 sites nearby. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Kemmerer
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Kemmerer Average
- ●USDA Zones 5a-6b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Kemmerer
Pull a site-specific report for your exact address in Kemmerer, Wyoming — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Kemmerer, Wyoming
- USDA Hardiness Zones: 5a-6b (USDA PHZM 2023)
- Last Hard Freeze (28°F): May 14 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Sep 26 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~135 (town normal, NOAA 1991–2020 Climate Normals)
- Land Area: 5K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.
Frequently Asked Questions
What hardiness zone is Kemmerer, Wyoming?
Kemmerer sits in USDA hardiness zones 5a-6b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Kemmerer?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 26 — long-season crops need about 90 days of runway, quick greens only 30. Even here the calendar’s edges hold value: thirty-day greens late in the window, then garlic and a rested bed for spring.
When does frost risk typically end in Kemmerer?
The last hard freeze (28°F) in Kemmerer typically lands around May 14, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
When is the first frost in Kemmerer?
The first hard freeze (28°F) in Kemmerer typically arrives around Sep 26, per NOAA 1991–2020 climate normals — the point most tender summer crops finish. Lighter frosts usually reach a couple of weeks earlier, so watch the forecast from late summer on and harvest or cover tender plants before the first cold night.
What vegetables grow in Kemmerer?
Kemmerer's zones 5a-6b support a wide range — strong performers include Potato, Indian Paintbrush, Cottonwood, Rhubarb, and Chokecherry. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Kemmerer, really?
Officially, Kemmerer sits in USDA zones 5a-6b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Kemmerer?
The federal record around Kemmerer shows 84 documented sites — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do gardeners stretch the season in Kemmerer?
With about 135 frost-free days between hard freezes, Kemmerer rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder, cold frames and low tunnels more, and quick-maturing varieties make the arithmetic work. Starting transplants indoors ahead of the May 14 hard-freeze normal stretches the season without touching the calendar.
Everything on this page is a Kemmerer average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
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