Arapahoe, Wyoming, sits in USDA hardiness zone 4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Growers here do well with cabbage, cranberry, turkish rocket, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Arapahoe, 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 Arapahoe lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Arapahoe — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Arapahoe — the short answer
Arapahoe, Wyoming: USDA zone 4b, about 152 days between hard freezes, across 18K acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~152
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 18K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 4b is Arapahoe's average, not your lot's — a low corner or a tree line moves it. Against Arapahoe's 152-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Arapahoe
Each reading below is measured for Arapahoe itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredArapahoe runs about 152 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredArapahoe sits in USDA hardiness zone 4b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Arapahoe is in
Arapahoe sits in the Wyoming Basin — EPA Level III, inside the wider North American Deserts. That is read at Arapahoe's own centroid rather than borrowed from Fremont County.
What Grows in Arapahoe
Every plant below cleared Arapahoe's own zone 4b and its 152-day season. Each card opens that plant's Wyoming profile. How we score.
Is it too late to plant in Arapahoe?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 6; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 3 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Arapahoe
Closest first, within ~10 miles of Arapahoe. Listing isn't leaking, and distance isn't exposure.
- WESTERN WYOMING OILBrownfields · 1.3 mi
- ARAPAHOE HEALTH CENTERBrownfields · 1.7 mi
- CHEMTRADE REFINERY SERVICES INC - RIVERTON PLANTToxics Release Inventory · 1.9 mi
- CHEMTRADE REFINERY SERVICES INC - RIVERTON PLANTBrownfields · 1.9 mi
- Arapahoe Post OfficeUnderground Storage Tanks · 1.9 mi
- 1N-04E-32bda01Nitrate · 2.3 mi
- 1S-03E-24cba01Nitrate · 2.5 mi
- 1N-04E-32adb01Nitrate · 2.5 mi
- Porter's Mountain View SupplyUnderground Storage Tanks · 2.7 mi
- Fremont County School District #38Underground Storage Tanks · 2.8 mi
- Davis Funeral Home, Inc.Underground Storage Tanks · 2.9 mi
- Central Wyoming CollegeUnderground Storage Tanks · 2.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Arapahoe's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Arapahoe.
Total Sites
219
within ~10 miles of Arapahoe
Risk Level
Elevated
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Arapahoe
Severity Distribution
within ~10 miles of Arapahoe
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Arapahoe
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Arapahoe average
Your land is one point inside Arapahoe
Everything above resolves to Arapahoe as a whole — one PHZM band and one 28°F frost record, read across 18K acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Arapahoe Average
Arapahoe Average
- ●USDA Zones 4b, averaged across Arapahoe
- ●One soil character for all of Arapahoe
- ●Frost dates read at Arapahoe's scale: May 4 to Oct 3
YOUR Parcel
- ✓Your exact zone, not Arapahoe's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Arapahoe
Pull a site-specific report for your exact address in Arapahoe, Wyoming — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Arapahoe averages can't show:
We read public map data around Arapahoe — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Arapahoe average
How we know this about Arapahoe
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Arapahoe’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Arapahoe
When does frost risk typically end in Arapahoe?
The last hard freeze (28°F) in Arapahoe typically lands around May 4, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about May 25.
When is the first frost in Arapahoe?
The first hard freeze (28°F) in Arapahoe typically arrives around Oct 3, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 19, so the watching starts about Sep 3 — about 152 days after the spring freeze cleared.
How long is the growing season in Arapahoe?
Measured between 28°F hard freezes, Arapahoe sees about 152 frost-free days — roughly May 4 through Oct 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 25 to Sep 19, about 117 days.
Is the soil safe to grow vegetables in Arapahoe?
The federal record around Arapahoe is a meaningful one — 219 documented sites, mostly Underground Storage Tanks entries (112), the nearest Brownfields record about 1.3 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Arapahoe?
From about Sep 3 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Oct 3 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Oct 3. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Arapahoe's scale — its 4b band and its 152-day season. Your yard writes its own version of Arapahoe's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Arapahoe’s own scale
6 of the readings below were taken at Arapahoe's own scale — its own ~152-day season between 28°F freezes, the 17,689 acres it covers and 219 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Arapahoe's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Arapahoe's own 28°F hard-freeze dates, about May 4 and Oct 3 and the ~152-day span between themNOAA 1991–2020 Climate Normals
- 219 documented contamination sites on the federal record near Arapahoe, the closest Brownfields record about 1.3 miles out from the town centreFederal environmental registers
- Arapahoe's boundary and the 17,689 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~152-day seasonGrowable Ground crop-matching engine
- The ecoregion at Arapahoe's own centroid, the Wyoming BasinUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Arapahoe's 17,689 acres read through its county's SSURGO summaryfrom Fremont County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Fremont County
- The growing challenges every Wyoming grower plans around — written at state scale, so they stay on the state guidefrom Wyoming
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Fremont County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Arapahoe's 17,689 acreswhy one lot differs from the next →
- Which side of Arapahoe you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 17,689 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 1.3 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Arapahoe-wide figureread your own land →
More in Wyoming
Wider growing context
What grows across WyomingArapahoe sits outside our named growing regions, so Wyoming as a whole is its closest context here.