Azure, Montana, sits in USDA hardiness zone 4a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor cabbage, cranberry, cilantro, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Azure, 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 Azure 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 Azure — soil, climate, flood, and parcel records. How we handle your address.
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Azure — the short answer
Azure, Montana: USDA zone 4a, about 136 days between hard freezes, across 3K acres of town.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~136
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 3K 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 4a is Azure's average, not your lot's — a low corner or a tree line moves it. Against Azure's 136-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Azure
Each reading below is measured for Azure itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAzure runs about 136 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredAzure sits in USDA hardiness zone 4a.
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 Azure is in
Azure sits in the Northwestern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Azure's own centroid rather than borrowed from Hill County.
What Grows in Azure
Every plant below cleared Azure's own zone 4a and its 136-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Azure?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 15; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 13 (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. Short seasons reward decisiveness — quick-maturing varieties late, hardy greens under cover, and next year’s garlic in the ground before it closes.
What's on the federal record near Azure
Closest first, within ~10 miles of Azure. Listing isn't leaking, and distance isn't exposure.
- OATS ROAD DRUMSSuperfund · 2.6 mi
- ROCKY BOY ELEMENTARY SCHOOLUnderground Storage Tanks · 3.5 mi
- ROCKY BOY AGENCY SHOPUnderground Storage Tanks · 3.6 mi
- VILLAGE GROCERYUnderground Storage Tanks · 3.7 mi
- GRAIN & CATTLE CORPUnderground Storage Tanks · 3.7 mi
- OLD CORNER GROCERYUnderground Storage Tanks · 3.7 mi
- LAMERES STATIONUnderground Storage Tanks · 3.7 mi
- SQUAW BUTTE MICROWAVE SITEUnderground Storage Tanks · 3.7 mi
- FRANK & OREL M SHERERUnderground Storage Tanks · 3.7 mi
- ORDEAN SOLBERGUnderground Storage Tanks · 3.7 mi
- 31N15E34CCCB01Nitrate · 6.5 mi
- FRIEDES HWY MARKETUnderground Storage Tanks · 8.0 mi
4 more sites are on the record inside the same radius. See them on the map
Measured from Azure'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 Azure.
Total Sites
17
within ~10 miles of Azure
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Azure
Severity Distribution
within ~10 miles of Azure
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Mine waste leaches heavy metals. Test for lead, arsenic and cadmium before growing food here.
Check your specific parcel in Azure
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 Azure average
Your land is one point inside Azure
Everything above resolves to Azure as a whole — one PHZM band and one 28°F frost record, read across 3K 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 Azure Average
Azure Average
- ●USDA Zones 4a, averaged across Azure
- ●One soil character for all of Azure
- ●Frost dates read at Azure's scale: May 13 to Sep 26
YOUR Parcel
- ✓Your exact zone, not Azure's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Azure
Pull a site-specific report for your exact address in Azure, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Azure averages can't show:
We read public map data around Azure — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Azure average
How we know this about Azure
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 Azure’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 Azure
When does frost risk typically end in Azure?
The last hard freeze (28°F) in Azure typically lands around May 13, 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 Jun 3.
When is the first frost in Azure?
The first hard freeze (28°F) in Azure typically arrives around Sep 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 12, so the watching starts about Aug 27 — about 136 days after the spring freeze cleared.
How long is the growing season in Azure?
Measured between 28°F hard freezes, Azure sees about 136 frost-free days — roughly May 13 through Sep 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 3 to Sep 12, about 101 days.
Is the soil safe to grow vegetables in Azure?
The federal record around Azure is a meaningful one — 17 documented sites, mostly Underground Storage Tanks entries (13), the nearest Superfund record about 2.6 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 gardeners stretch the season in Azure?
With about 136 frost-free days between hard freezes, Azure rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 164 to 192 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 13 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Azure's scale — its 4a band and its 136-day season. Your yard writes its own version of Azure'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 Azure’s own scale
6 of the readings below were taken at Azure's own scale — its own ~136-day season between 28°F freezes, the 2,878 acres it covers and 17 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Azure's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Azure's own 28°F hard-freeze dates, about May 13 and Sep 26 and the ~136-day span between themNOAA 1991–2020 Climate Normals
- 17 documented contamination sites on the federal record near Azure, the closest Superfund record about 2.6 miles out from the town centreFederal environmental registers
- Azure's boundary and the 2,878 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~136-day seasonGrowable Ground crop-matching engine
- The ecoregion at Azure's own centroid, the Northwestern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Azure's 2,878 acres read through its county's SSURGO summaryfrom Hill County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Hill 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 Hill County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Azure's 2,878 acreswhy one lot differs from the next →
- Which side of Azure you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,878 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Superfund record about 2.6 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 Azure-wide figureread your own land →
More in Montana
Growing region
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