Chinook, Montana, sits in USDA hardiness zone 3b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: cabbage, cranberry, turkish rocket, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Chinook, 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 Chinook 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 Chinook — soil, climate, flood, and parcel records. How we handle your address.
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Chinook — the short answer
Chinook, Montana: USDA zone 3b, about 150 days between hard freezes, across 335 acres of city.
- USDA zone
- 3b
- 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 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~150
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 335 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 3b is Chinook's average, not your lot's — a low corner or a tree line moves it. Against Chinook's 150-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Chinook
Each reading below is measured for Chinook itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredChinook 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
MeasuredChinook sits in USDA hardiness zone 3b.
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 Chinook is in
Chinook sits in the Northwestern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Chinook's own centroid rather than borrowed from Blaine County.
What Grows in Chinook
Every plant below cleared Chinook's own zone 3b and its 150-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Chinook?
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 1 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Chinook
Closest first, within ~10 miles of Chinook. Listing isn't leaking, and distance isn't exposure.
- ANDYS EXXONUnderground Storage Tanks · 400 ft
- CHINOOK SCHOOL DISTRICT 10Brownfields · 550 ft
- OBIE FLYING SERVICEUnderground Storage Tanks · 900 ft
- BOX ELDER CAMPUnderground Storage Tanks · 900 ft
- RICHARD S TILLEMANUnderground Storage Tanks · 900 ft
- CLEVELAND BARUnderground Storage Tanks · 900 ft
- BOWES FIELDUnderground Storage Tanks · 900 ft
- ORGANIZATIONAL MAINT SHOP 7Underground Storage Tanks · 900 ft
- WASTEWATER TREATMENT PLANT CHINOOKUnderground Storage Tanks · 1100 ft
- DAVES EXXON SERVICEUnderground Storage Tanks · 1100 ft
- BLAINE COUNTY COURTHOUSEUnderground Storage Tanks · 1100 ft
- BLAINE COUNTY ROAD DEPTUnderground Storage Tanks · 1500 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Chinook'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 Chinook.
Total Sites
59
within ~10 miles of Chinook
Risk Level
Moderate
Highest-severity
1 concentrated animal feeding operation
Sources Checked
within ~10 miles of Chinook
Severity Distribution
within ~10 miles of Chinook
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Chinook, Nitrate runs higher than the national average — 30 sites within ~10 miles of Chinook. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Chinook
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 Chinook average
Your land is one point inside Chinook
Everything above resolves to Chinook as a whole — one PHZM band and one 28°F frost record, read across 335 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 city 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 Chinook Average
Chinook Average
- ●USDA Zones 3b, averaged across Chinook
- ●One soil character for all of Chinook
- ●Frost dates read at Chinook's scale: May 4 to Oct 1
YOUR Parcel
- ✓Your exact zone, not Chinook's 3b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Chinook
Pull a site-specific report for your exact address in Chinook, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Chinook averages can't show:
We read public map data around Chinook — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Chinook average
How we know this about Chinook
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Chinook’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 city grain anywhere on this page — there is no city-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 Chinook
When does frost risk typically end in Chinook?
The last hard freeze (28°F) in Chinook 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 Chinook?
The first hard freeze (28°F) in Chinook typically arrives around Oct 1, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 17, so the watching starts about Sep 1 — about 150 days after the spring freeze cleared.
How long is the growing season in Chinook?
Measured between 28°F hard freezes, Chinook sees about 150 frost-free days — roughly May 4 through Oct 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 25 to Sep 17, about 115 days.
Is the soil safe to grow vegetables in Chinook?
The federal record around Chinook shows 59 documented sites, mostly Nitrate entries (30), the nearest Underground Storage Tanks record under a tenth of a mile out — 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 I protect my plants from frost in Chinook?
From about Sep 1 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 1 (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 1. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Chinook's scale — its 3b band and its 150-day season. Your yard writes its own version of Chinook'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 Chinook’s own scale
6 of the readings below were taken at Chinook's own scale — its own ~150-day season between 28°F freezes, the 335 acres it covers and 59 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Chinook's own USDA hardiness band, zones 3bUSDA PHZM 2023
- Chinook's own 28°F hard-freeze dates, about May 4 and Oct 1 and the ~150-day span between themNOAA 1991–2020 Climate Normals
- 59 documented contamination sites on the federal record near Chinook, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Chinook's boundary and the 335 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 3b and a ~150-day seasonGrowable Ground crop-matching engine
- The ecoregion at Chinook's own centroid, the Northwestern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Chinook's 335 acres read through its county's SSURGO summaryfrom Blaine County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Blaine County
- The growing challenges every Montana grower plans around — written at state scale, so they stay on the state guidefrom Montana
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Blaine County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Chinook's 335 acreswhy one lot differs from the next →
- Which side of Chinook you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 335 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Chinook-wide figureread your own land →
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