Mobridge, South Dakota, sits in USDA hardiness zone 4b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Growers here do well with cabbage, cranberry, turkish rocket, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Mobridge, 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 Mobridge 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 Mobridge — soil, climate, flood, and parcel records. How we handle your address.
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Mobridge — the short answer
Mobridge, South Dakota: USDA zone 4b, about 168 days between hard freezes, across 1K acres of city.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~168
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 1K 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 Mobridge's average, not your lot's — a low corner or a tree line moves it. Against Mobridge's 168-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Mobridge
Each reading below is measured for Mobridge itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMobridge runs about 168 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
MeasuredMobridge 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 Mobridge is in
Mobridge sits in the Northwestern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Mobridge's own centroid rather than borrowed from Walworth County.
What Grows in Mobridge
Every plant below cleared Mobridge's own zone 4b and its 168-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Mobridge?
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 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 12 — 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 Mobridge
Closest first, within ~10 miles of Mobridge. Listing isn't leaking, and distance isn't exposure.
- BURLINGTON NORTHERN RAILROADUnderground Storage Tanks · 350 ft
- GRAND CENTRALUnderground Storage Tanks · 1300 ft
- CLARKUnderground Storage Tanks · 1300 ft
- SHAMROCKUnderground Storage Tanks · 1400 ft
- MOTT AERIAL SPRAYBrownfields · 1400 ft
- GTC AUTO PARTS INCBrownfields · 1500 ft
- RON'S REPAIRUnderground Storage Tanks · 2000 ft
- BRIDGE CITY BAITUnderground Storage Tanks · 2100 ft
- OAHE BAIT-N-BOAT SERVICEUnderground Storage Tanks · 2200 ft
- GAS STOPUnderground Storage Tanks · 2200 ft
- TODDS AUTO SERVICE INCUnderground Storage Tanks · 2500 ft
- G & R BODY SHOPBrownfields · 2500 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Mobridge'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 Mobridge.
Total Sites
58
within ~10 miles of Mobridge
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Mobridge
Severity Distribution
within ~10 miles of Mobridge
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mobridge, Nitrate runs higher than the national average — 24 sites within ~10 miles of Mobridge. 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 Mobridge
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 Mobridge average
Your land is one point inside Mobridge
Everything above resolves to Mobridge as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Mobridge Average
Mobridge Average
- ●USDA Zones 4b, averaged across Mobridge
- ●One soil character for all of Mobridge
- ●Frost dates read at Mobridge's scale: Apr 27 to Oct 12
YOUR Parcel
- ✓Your exact zone, not Mobridge's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mobridge
Pull a site-specific report for your exact address in Mobridge, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mobridge averages can't show:
We read public map data around Mobridge — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mobridge average
How we know this about Mobridge
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 Mobridge’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 Mobridge
When does frost risk typically end in Mobridge?
The last hard freeze (28°F) in Mobridge typically lands around Apr 27, 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 18.
When is the first frost in Mobridge?
The first hard freeze (28°F) in Mobridge typically arrives around Oct 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 28, so the watching starts about Sep 12 — about 168 days after the spring freeze cleared.
How long is the growing season in Mobridge?
Measured between 28°F hard freezes, Mobridge sees about 168 frost-free days — roughly Apr 27 through Oct 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 18 to Sep 28, about 133 days.
Is the soil safe to grow vegetables in Mobridge?
The federal record around Mobridge shows 58 documented sites, mostly Underground Storage Tanks entries (26), 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 Mobridge?
From about Sep 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Mobridge's scale — its 4b band and its 168-day season. Your yard writes its own version of Mobridge'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 Mobridge’s own scale
6 of the readings below were taken at Mobridge's own scale — its own ~168-day season between 28°F freezes, the 1,254 acres it covers and 58 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Mobridge's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Mobridge's own 28°F hard-freeze dates, about Apr 27 and Oct 12 and the ~168-day span between themNOAA 1991–2020 Climate Normals
- 58 documented contamination sites on the federal record near Mobridge, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Mobridge's boundary and the 1,254 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~168-day seasonGrowable Ground crop-matching engine
- The ecoregion at Mobridge's own centroid, the Northwestern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Mobridge's 1,254 acres read through its county's SSURGO summaryfrom Walworth County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Walworth 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 Walworth County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Mobridge's 1,254 acreswhy one lot differs from the next →
- Which side of Mobridge you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,254 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 Mobridge-wide figureread your own land →
More in South Dakota
Wider growing context
What grows across South DakotaMobridge sits outside our named growing regions, so South Dakota as a whole is its closest context here.
Nearby growing guides