Centralia, Iowa, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Centralia, 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 Centralia 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 Centralia — soil, climate, flood, and parcel records. How we handle your address.
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Centralia — the short answer
Centralia, Iowa: USDA zone 5a, about 192 days between hard freezes, across 397 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~192
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 397 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 Centralia's average, not your lot's — a low corner or a tree line moves it. Against Centralia's 192-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Centralia
Each reading below is measured for Centralia itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCentralia runs about 192 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
MeasuredCentralia 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 Centralia is in
Centralia sits in the Driftless Area — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Centralia's own centroid rather than borrowed from Dubuque County.
What Grows in Centralia
Every plant below cleared Centralia's own zone 5a and its 192-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Centralia?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 22 — 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 Centralia
Closest first, within ~10 miles of Centralia. Listing isn't leaking, and distance isn't exposure.
- THREE RIVERS FS COMPANYUnderground Storage Tanks · 1.6 mi
- COUNTRY STOREUnderground Storage Tanks · 1.6 mi
- NORTHEAST IOWA TECHNICAL INSTITUTEUnderground Storage Tanks · 1.8 mi
- MCDERMOTT EXCAVATINGUnderground Storage Tanks · 1.8 mi
- SWISS VALLEY PARKUnderground Storage Tanks · 1.8 mi
- THUNDER HILLS COUNTRY CLUBUnderground Storage Tanks · 1.8 mi
- NE IOWA COMMUNITY COLLEGE - PEOSTABrownfields · 2.0 mi
- CAPTIVE PLASTICSBrownfields · 2.0 mi
- CASEYS GENERAL STOREUnderground Storage Tanks · 2.1 mi
- MI-T-M CORPORATIONUnderground Storage Tanks · 2.1 mi
- KWIK STOPUnderground Storage Tanks · 2.2 mi
- ROADWAY EXPRESS INCUnderground Storage Tanks · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Centralia'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 Centralia.
Sources Checked
within ~10 miles of Centralia
Severity Distribution
within ~10 miles of Centralia
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Centralia, Toxics Release Inventory runs higher than the national average — 34 sites within ~10 miles of Centralia. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Centralia
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 Centralia average
Your land is one point inside Centralia
Everything above resolves to Centralia as a whole — one PHZM band and one 28°F frost record, read across 397 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 Centralia Average
Centralia Average
- ●USDA Zones 5a, averaged across Centralia
- ●One soil character for all of Centralia
- ●Frost dates read at Centralia's scale: Apr 13 to Oct 22
YOUR Parcel
- ✓Your exact zone, not Centralia's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Centralia
Pull a site-specific report for your exact address in Centralia, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Centralia averages can't show:
We read public map data around Centralia — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Centralia average
How we know this about Centralia
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 Centralia’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 Centralia
When does frost risk typically end in Centralia?
The last hard freeze (28°F) in Centralia typically lands around Apr 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 May 4.
When is the first frost in Centralia?
The first hard freeze (28°F) in Centralia typically arrives around Oct 22, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 8, so the watching starts about Sep 22 — about 192 days after the spring freeze cleared.
How long is the growing season in Centralia?
Measured between 28°F hard freezes, Centralia sees about 192 frost-free days — roughly Apr 13 through Oct 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 4 to Oct 8, about 157 days.
Is the soil safe to grow vegetables in Centralia?
The federal record around Centralia runs heavier than most — 486 documented sites, mostly Underground Storage Tanks entries (260), the nearest Underground Storage Tanks record about 1.6 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Centralia?
From about Sep 22 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 22 (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 22. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Centralia's scale — its 5a band and its 192-day season. Your yard writes its own version of Centralia'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 Centralia’s own scale
6 of the readings below were taken at Centralia's own scale — its own ~192-day season between 28°F freezes, the 397 acres it covers and 486 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Centralia's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Centralia's own 28°F hard-freeze dates, about Apr 13 and Oct 22 and the ~192-day span between themNOAA 1991–2020 Climate Normals
- 486 documented contamination sites on the federal record near Centralia, the closest Underground Storage Tanks record about 1.6 miles out from the town centreFederal environmental registers
- Centralia's boundary and the 397 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~192-day seasonGrowable Ground crop-matching engine
- The ecoregion at Centralia's own centroid, the Driftless AreaUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Centralia's 397 acres read through its county's SSURGO summaryfrom Dubuque County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Dubuque 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 Dubuque County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Centralia's 397 acreswhy one lot differs from the next →
- Which side of Centralia you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 397 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 1.6 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 Centralia-wide figureread your own land →
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