Interior, South Dakota, sits in USDA hardiness zone 5a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include cabbage, cranberry, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Interior, 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 Interior 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 Interior — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Interior — the short answer
Interior, South Dakota: USDA zone 5a, about 169 days between hard freezes, across 857 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~169
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 857 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 Interior's average, not your lot's — a low corner or a tree line moves it. Against Interior's 169-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Interior
Each reading below is measured for Interior itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredInterior runs about 169 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
MeasuredInterior 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 Interior is in
Interior sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. That is read at Interior's own centroid rather than borrowed from Jackson County.
What Grows in Interior
Every plant below cleared Interior's own zone 5a and its 169-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Interior?
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 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 14 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
What's on the federal record near Interior
Closest first, within ~10 miles of Interior. Listing isn't leaking, and distance isn't exposure.
- WAGON WHEEL BARUnderground Storage Tanks · 700 ft
- U.S. NATL. PARK SERVICE BADLANDS NATIONAL PARKToxics Release Inventory · 2.5 mi
- D-10Underground Storage Tanks · 3.9 mi
- D-6Underground Storage Tanks · 5.8 mi
- NATIONAL PARK SERVICEUnderground Storage Tanks · 5.9 mi
- USNPS-BADLANDS NATIONAL PARKBrownfields · 7.3 mi
- 42N39W15ACADNitrate · 7.9 mi
- BADLANDS TRADING POST- BPUnderground Storage Tanks · 8.4 mi
- CACTUS FLATUnderground Storage Tanks · 8.6 mi
- D-7Underground Storage Tanks · 9.0 mi
Measured from Interior'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 Interior.
Total Sites
11
within ~10 miles of Interior
Risk Level
Low
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Interior
Severity Distribution
within ~10 miles of Interior
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.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Interior
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 Interior average
Your land is one point inside Interior
Everything above resolves to Interior as a whole — one PHZM band and one 28°F frost record, read across 857 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 Interior Average
Interior Average
- ●USDA Zones 5a, averaged across Interior
- ●One soil character for all of Interior
- ●Frost dates read at Interior's scale: Apr 28 to Oct 14
YOUR Parcel
- ✓Your exact zone, not Interior's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Interior
Pull a site-specific report for your exact address in Interior, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Interior averages can't show:
We read public map data around Interior — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Interior average
How we know this about Interior
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 Interior’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 Interior
When does frost risk typically end in Interior?
The last hard freeze (28°F) in Interior typically lands around Apr 28, 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 19.
When is the first frost in Interior?
The first hard freeze (28°F) in Interior typically arrives around Oct 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 30, so the watching starts about Sep 14 — about 169 days after the spring freeze cleared.
How long is the growing season in Interior?
Measured between 28°F hard freezes, Interior sees about 169 frost-free days — roughly Apr 28 through Oct 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Sep 30, about 134 days.
Is the soil safe to grow vegetables in Interior?
The federal record around Interior is light — 11 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (7), the nearest Underground Storage Tanks record about 0.1 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Interior?
From about Sep 14 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 14 (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 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Interior's scale — its 5a band and its 169-day season. Your yard writes its own version of Interior'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 Interior’s own scale
6 of the readings below were taken at Interior's own scale — its own ~169-day season between 28°F freezes, the 857 acres it covers and 11 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Interior's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Interior's own 28°F hard-freeze dates, about Apr 28 and Oct 14 and the ~169-day span between themNOAA 1991–2020 Climate Normals
- 11 documented contamination sites on the federal record near Interior, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Interior's boundary and the 857 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~169-day seasonGrowable Ground crop-matching engine
- The ecoregion at Interior's own centroid, the Northwestern Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Interior's 857 acres read through its county's SSURGO summaryfrom Jackson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jackson 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 Jackson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Interior's 857 acreswhy one lot differs from the next →
- Which side of Interior you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 857 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Interior-wide figureread your own land →
More in South Dakota
Growing region
Nearby growing guides