Timber Lake, South Dakota, sits in USDA hardiness zone 4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include cabbage, cranberry, turkish rocket, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Timber Lake, 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 Timber Lake 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 Timber Lake — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Timber Lake — the short answer
Timber Lake, South Dakota: USDA zone 4b, about 164 days between hard freezes, across 391 acres of city.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~164
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 391 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 Timber Lake's average, not your lot's — a low corner or a tree line moves it. Against Timber Lake's 164-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Timber Lake
Each reading below is measured for Timber Lake itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredTimber Lake runs about 164 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
MeasuredTimber Lake 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 Timber Lake is in
Timber Lake sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. That is read at Timber Lake's own centroid rather than borrowed from Dewey County.
What Grows in Timber Lake
Every plant below cleared Timber Lake's own zone 4b and its 164-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Timber Lake?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 10 — 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 Timber Lake
Closest first, within ~10 miles of Timber Lake. Listing isn't leaking, and distance isn't exposure.
- TIMBER LAKE SERVICEUnderground Storage Tanks · 600 ft
- HERMAN SERVICEUnderground Storage Tanks · 1000 ft
- 17N25E20BBNitrate · 2100 ft
- 17N25E20BCABNitrate · 2400 ft
- 17N25E20Nitrate · 2600 ft
- 17N25E20 (3)Nitrate · 2600 ft
- 17N25E20 (2)Nitrate · 2600 ft
- 17N25E20BCNitrate · 0.5 mi
- DEWEY CO HWY DEPTUnderground Storage Tanks · 0.8 mi
- 17N25E13ABACNitrate · 4.4 mi
- 17N25E 1BAAANitrate · 5.0 mi
- 018N25E14DDDDNitrate · 7.0 mi
4 more sites are on the record inside the same radius. See them on the map
Measured from Timber Lake'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 Timber Lake.
Total Sites
29
within ~10 miles of Timber Lake
Risk Level
Low
Highest-severity
26 nitrate monitoring sites
Severity Distribution
within ~10 miles of Timber Lake
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Timber Lake, Nitrate runs higher than the national average — 26 sites within ~10 miles of Timber Lake. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 Timber Lake
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 Timber Lake average
Your land is one point inside Timber Lake
Everything above resolves to Timber Lake as a whole — one PHZM band and one 28°F frost record, read across 391 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 Timber Lake Average
Timber Lake Average
- ●USDA Zones 4b, averaged across Timber Lake
- ●One soil character for all of Timber Lake
- ●Frost dates read at Timber Lake's scale: Apr 29 to Oct 10
YOUR Parcel
- ✓Your exact zone, not Timber Lake's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Timber Lake
Pull a site-specific report for your exact address in Timber Lake, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Timber Lake averages can't show:
We read public map data around Timber Lake — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Timber Lake average
How we know this about Timber Lake
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 Timber Lake’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 Timber Lake
When does frost risk typically end in Timber Lake?
The last hard freeze (28°F) in Timber Lake typically lands around Apr 29, 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 20.
When is the first frost in Timber Lake?
The first hard freeze (28°F) in Timber Lake typically arrives around Oct 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 26, so the watching starts about Sep 10 — about 164 days after the spring freeze cleared.
How long is the growing season in Timber Lake?
Measured between 28°F hard freezes, Timber Lake sees about 164 frost-free days — roughly Apr 29 through Oct 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 20 to Sep 26, about 129 days.
Is the soil safe to grow vegetables in Timber Lake?
The federal record around Timber Lake is light — 29 documented sites across the 9 federal source types we checked, mostly Nitrate entries (26), 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 Timber Lake?
From about Sep 10 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Timber Lake's scale — its 4b band and its 164-day season. Your yard writes its own version of Timber Lake'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 Timber Lake’s own scale
6 of the readings below were taken at Timber Lake's own scale — its own ~164-day season between 28°F freezes, the 391 acres it covers and 29 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Timber Lake's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Timber Lake's own 28°F hard-freeze dates, about Apr 29 and Oct 10 and the ~164-day span between themNOAA 1991–2020 Climate Normals
- 29 documented contamination sites on the federal record near Timber Lake, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Timber Lake's boundary and the 391 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~164-day seasonGrowable Ground crop-matching engine
- The ecoregion at Timber Lake's own centroid, the Northwestern Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Timber Lake's 391 acres read through its county's SSURGO summaryfrom Dewey County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Dewey 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 Dewey County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Timber Lake's 391 acreswhy one lot differs from the next →
- Which side of Timber Lake you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 391 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 Timber Lake-wide figureread your own land →
More in South Dakota
Growing region
Nearby growing guides