Bairoil, Wyoming, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Reliable performers under these conditions include cabbage, cranberry, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Bairoil, 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 Bairoil 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 Bairoil — soil, climate, flood, and parcel records. How we handle your address.
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Bairoil — the short answer
Bairoil, Wyoming: USDA zone 5a, about 150 days between hard freezes, across 905 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 9
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 6
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~150
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 905 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 5a is Bairoil's average, not your lot's — a low corner or a tree line moves it. Against Bairoil's 150-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Bairoil
Each reading below is measured for Bairoil itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBairoil runs about 150 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
MeasuredBairoil sits in USDA hardiness zone 5a.
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 Bairoil is in
Bairoil sits in the Wyoming Basin — EPA Level III, inside the wider North American Deserts. That is read at Bairoil's own centroid rather than borrowed from Sweetwater County.
What Grows in Bairoil
Every plant below cleared Bairoil's own zone 5a and its 150-day season. Each card opens that plant's Wyoming profile. How we score.
Is it too late to plant in Bairoil?
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 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 9 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 6 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
What's on the federal record near Bairoil
Closest first, within ~10 miles of Bairoil. Listing isn't leaking, and distance isn't exposure.
- LITTLE AMERICA WESTBrownfields · 550 ft
- The StoreUnderground Storage Tanks · 1100 ft
- Amoco Production CompanyUnderground Storage Tanks · 1200 ft
- 26-090-11bbc01Nitrate · 0.5 mi
- BLM-BAROIL LANDFILLSuperfund · 0.8 mi
- Old Wertz Gas PlantUnderground Storage Tanks · 1.9 mi
- 26-090-07cda01Nitrate · 3.5 mi
- 26-089-16cdb01Nitrate · 4.4 mi
- Dick's Standard ServiceUnderground Storage Tanks · 4.5 mi
- 26-091-10dca01Nitrate · 6.3 mi
- 25-090-16aca01Nitrate · 6.7 mi
- 27-089-15cac01Nitrate · 7.2 mi
2 more sites are on the record inside the same radius. See them on the map
Measured from Bairoil'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 Bairoil.
Total Sites
23
within ~10 miles of Bairoil
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Bairoil
Severity Distribution
within ~10 miles of Bairoil
Highest-Severity Sites
Know Before You Grow
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •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.
Check your specific parcel in Bairoil
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 Bairoil average
Your land is one point inside Bairoil
Everything above resolves to Bairoil as a whole — one PHZM band and one 28°F frost record, read across 905 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 Bairoil Average
Bairoil Average
- ●USDA Zones 5a, averaged across Bairoil
- ●One soil character for all of Bairoil
- ●Frost dates read at Bairoil's scale: May 9 to Oct 6
YOUR Parcel
- ✓Your exact zone, not Bairoil's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Bairoil
Pull a site-specific report for your exact address in Bairoil, Wyoming — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Bairoil averages can't show:
We read public map data around Bairoil — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Bairoil average
How we know this about Bairoil
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 Bairoil’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 Bairoil
When does frost risk typically end in Bairoil?
The last hard freeze (28°F) in Bairoil typically lands around May 9, 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 30.
When is the first frost in Bairoil?
The first hard freeze (28°F) in Bairoil typically arrives around Oct 6, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 22, so the watching starts about Sep 6 — about 150 days after the spring freeze cleared.
How long is the growing season in Bairoil?
Measured between 28°F hard freezes, Bairoil sees about 150 frost-free days — roughly May 9 through Oct 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 30 to Sep 22, about 115 days.
Is the soil safe to grow vegetables in Bairoil?
The federal record around Bairoil is a meaningful one — 23 documented sites, mostly Nitrate entries (16), the nearest Brownfields record about 0.1 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 Bairoil?
From about Sep 6 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 6 (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 6. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Bairoil's scale — its 5a band and its 150-day season. Your yard writes its own version of Bairoil'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 Bairoil’s own scale
6 of the readings below were taken at Bairoil's own scale — its own ~150-day season between 28°F freezes, the 905 acres it covers and 23 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Bairoil's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Bairoil's own 28°F hard-freeze dates, about May 9 and Oct 6 and the ~150-day span between themNOAA 1991–2020 Climate Normals
- 23 documented contamination sites on the federal record near Bairoil, the closest Brownfields record about 0.1 miles out from the town centreFederal environmental registers
- Bairoil's boundary and the 905 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~150-day seasonGrowable Ground crop-matching engine
- The ecoregion at Bairoil's own centroid, the Wyoming BasinUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Bairoil's 905 acres read through its county's SSURGO summaryfrom Sweetwater County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Sweetwater 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 Sweetwater County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Bairoil's 905 acreswhy one lot differs from the next →
- Which side of Bairoil you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 905 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.1 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 Bairoil-wide figureread your own land →
More in Wyoming
Wider growing context
What grows across WyomingBairoil sits outside our named growing regions, so Wyoming as a whole is its closest context here.
Nearby growing guides