Arion, Iowa, sits in USDA hardiness zone 5b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Growers here do well with cabbage, cranberry, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Arion, 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 Arion 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 Arion — soil, climate, flood, and parcel records. How we handle your address.
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Arion — the short answer
Arion, Iowa: USDA zone 5b, about 189 days between hard freezes, across 317 acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~189
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 317 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 5b is Arion's average, not your lot's — a low corner or a tree line moves it. Against Arion's 189-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Arion
Each reading below is measured for Arion itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredArion runs about 189 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
MeasuredArion sits in USDA hardiness zone 5b.
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 Arion is in
Arion sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Arion's own centroid rather than borrowed from Crawford County.
What Grows in Arion
Every plant below cleared Arion's own zone 5b and its 189-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Arion?
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 Mar 15; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 12 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 18 — 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 Arion
Closest first, within ~10 miles of Arion. Listing isn't leaking, and distance isn't exposure.
- 082N40W02ABDD 1910Arion 1Nitrate · 950 ft
- 082N40W02ABDD 1965Arion 2Nitrate · 950 ft
- 082N40W02ABDD 1925Arion 1Nitrate · 950 ft
- 083N40W35DDB 00571 1937Nitrate · 1800 ft
- 082N40W02AAC 1925ArionNitrate · 1900 ft
- 083N40W34BDD 1928Nitrate · 1.6 mi
- 083N40W34ABA 1934Nitrate · 1.6 mi
- ETTLEMAN OIL COMPANYUnderground Storage Tanks · 2.1 mi
- DOW CITY-ARION COMM SCHOOLUnderground Storage Tanks · 2.1 mi
- CENTRAL TELEPHONE COMPANYUnderground Storage Tanks · 2.2 mi
- CRAWFORD COUNTY HIGHWAY MAINTENANCE GARAGEUnderground Storage Tanks · 2.2 mi
- 082N40W10CBAB 39374 1928Dow City 1Nitrate · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Arion'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 Arion.
Total Sites
158
within ~10 miles of Arion
Risk Level
Moderate
Highest-severity
14 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Arion
Severity Distribution
within ~10 miles of Arion
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Arion, two things run higher than the national average within ~10 miles of Arion — Toxics Release Inventory (14 sites) and Nitrate (58 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Arion
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 Arion average
Your land is one point inside Arion
Everything above resolves to Arion as a whole — one PHZM band and one 28°F frost record, read across 317 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 Arion Average
Arion Average
- ●USDA Zones 5b, averaged across Arion
- ●One soil character for all of Arion
- ●Frost dates read at Arion's scale: Apr 12 to Oct 18
YOUR Parcel
- ✓Your exact zone, not Arion's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Arion
Pull a site-specific report for your exact address in Arion, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Arion averages can't show:
We read public map data around Arion — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Arion average
How we know this about Arion
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 Arion’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 Arion
When does frost risk typically end in Arion?
The last hard freeze (28°F) in Arion typically lands around Apr 12, 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 3.
When is the first frost in Arion?
The first hard freeze (28°F) in Arion typically arrives around Oct 18, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 4, so the watching starts about Sep 18 — about 189 days after the spring freeze cleared.
How long is the growing season in Arion?
Measured between 28°F hard freezes, Arion sees about 189 frost-free days — roughly Apr 12 through Oct 18, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 3 to Oct 4, about 154 days.
Is the soil safe to grow vegetables in Arion?
The federal record around Arion shows 158 documented sites, mostly Underground Storage Tanks entries (64), the nearest Nitrate record about 0.2 miles 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 Arion?
From about Sep 18 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 18 (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 18. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Arion's scale — its 5b band and its 189-day season. Your yard writes its own version of Arion'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 Arion’s own scale
6 of the readings below were taken at Arion's own scale — its own ~189-day season between 28°F freezes, the 317 acres it covers and 158 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Arion's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Arion's own 28°F hard-freeze dates, about Apr 12 and Oct 18 and the ~189-day span between themNOAA 1991–2020 Climate Normals
- 158 documented contamination sites on the federal record near Arion, the closest Nitrate record about 0.2 miles out from the town centreFederal environmental registers
- Arion's boundary and the 317 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~189-day seasonGrowable Ground crop-matching engine
- The ecoregion at Arion's own centroid, the Western Corn Belt PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Arion's 317 acres read through its county's SSURGO summaryfrom Crawford County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Crawford County
- The growing challenges every Iowa grower plans around — written at state scale, so they stay on the state guidefrom Iowa
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Crawford County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Arion's 317 acreswhy one lot differs from the next →
- Which side of Arion you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 317 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.2 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 Arion-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaArion sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides