Humboldt, South Dakota, sits in USDA hardiness zone 4b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor cabbage, cranberry, turkish rocket, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Humboldt, 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 Humboldt 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 Humboldt — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Humboldt — the short answer
Humboldt, South Dakota: USDA zone 4b, about 175 days between hard freezes, across 396 acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~175
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 396 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 4b is Humboldt's average, not your lot's — a low corner or a tree line moves it. Against Humboldt's 175-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Humboldt
Each reading below is measured for Humboldt itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHumboldt runs about 175 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
MeasuredHumboldt sits in USDA hardiness zone 4b.
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 Humboldt is in
Humboldt sits in the Northern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Humboldt's own centroid, and it is not what its county reads: Minnehaha County is mostly Western Corn Belt Plains. The wider page above you is answering a different question about different ground.
What Grows in Humboldt
Every plant below cleared Humboldt's own zone 4b and its 175-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Humboldt?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 13 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Humboldt
Closest first, within ~10 miles of Humboldt. Listing isn't leaking, and distance isn't exposure.
- 102N52W 9DCDDNitrate · 350 ft
- MARSH UNION CENTERUnderground Storage Tanks · 500 ft
- CENEX BULK PLANTUnderground Storage Tanks · 500 ft
- LUREX STANDARD STATIONUnderground Storage Tanks · 900 ft
- TOWN N' COUNTRYUnderground Storage Tanks · 1400 ft
- WEST CENTRAL SCHOOL DIST #49-7Underground Storage Tanks · 1900 ft
- LUDENS INC.Brownfields · 0.6 mi
- FRIENDLY'SUnderground Storage Tanks · 0.7 mi
- F.M. ACOUSTICAL TILE INCUnderground Storage Tanks · 3.0 mi
- 102N52W33CDDBNitrate · 3.9 mi
- 102N51W19DDADNitrate · 4.6 mi
- DAUGAARD GARAGEUnderground Storage Tanks · 5.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Humboldt'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 Humboldt.
Total Sites
74
within ~10 miles of Humboldt
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Humboldt
Severity Distribution
within ~10 miles of Humboldt
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Humboldt, Nitrate runs higher than the national average — 38 sites within ~10 miles of Humboldt. That's not a problem with your land — it's information about it.
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 Humboldt
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 Humboldt average
Your land is one point inside Humboldt
Everything above resolves to Humboldt as a whole — one PHZM band and one 28°F frost record, read across 396 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 Humboldt Average
Humboldt Average
- ●USDA Zones 4b, averaged across Humboldt
- ●One soil character for all of Humboldt
- ●Frost dates read at Humboldt's scale: Apr 21 to Oct 13
YOUR Parcel
- ✓Your exact zone, not Humboldt's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Humboldt
Pull a site-specific report for your exact address in Humboldt, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Humboldt averages can't show:
We read public map data around Humboldt — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Humboldt average
How we know this about Humboldt
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 Humboldt’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 Humboldt
When does frost risk typically end in Humboldt?
The last hard freeze (28°F) in Humboldt typically lands around Apr 21, 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 12.
When is the first frost in Humboldt?
The first hard freeze (28°F) in Humboldt typically arrives around Oct 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 29, so the watching starts about Sep 13 — about 175 days after the spring freeze cleared.
How long is the growing season in Humboldt?
Measured between 28°F hard freezes, Humboldt sees about 175 frost-free days — roughly Apr 21 through Oct 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 12 to Sep 29, about 140 days.
Is the soil safe to grow vegetables in Humboldt?
The federal record around Humboldt shows 74 documented sites, mostly Nitrate entries (38), the nearest Nitrate 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 Humboldt?
From about Sep 13 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 13 (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 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Humboldt's scale — its 4b band and its 175-day season. Your yard writes its own version of Humboldt'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 Humboldt’s own scale
6 of the readings below were taken at Humboldt's own scale — its own ~175-day season between 28°F freezes, the 396 acres it covers and 74 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Humboldt's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Humboldt's own 28°F hard-freeze dates, about Apr 21 and Oct 13 and the ~175-day span between themNOAA 1991–2020 Climate Normals
- 74 documented contamination sites on the federal record near Humboldt, the closest Nitrate record under a tenth of a mile out from the town centreFederal environmental registers
- Humboldt's boundary and the 396 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~175-day seasonGrowable Ground crop-matching engine
- Humboldt sits in the Northern Glaciated Plains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Humboldt's 396 acres read through its county's SSURGO summaryfrom Minnehaha County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Minnehaha County
- The growing challenges every South Dakota grower plans around — written at state scale, so they stay on the state guidefrom South Dakota
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Minnehaha County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Humboldt's 396 acreswhy one lot differs from the next →
- Which side of Humboldt you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 396 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 Humboldt-wide figureread your own land →