Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 57783 — Spearfish, SD

ZIP code 57783 (Spearfish, Lawrence County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 12 and the first fall frost October 2.

Where ZIP 57783 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostMay 12
First frostOct 2
2012 zone5a

Was 5a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Spearfish, SD…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Spearfish, SD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 12median — 50% chance of a later frost
Safe for tender plantsMay 25only 10% chance of frost after
First fall frostOctober 2median — 10% chance by Sep 21
Growing season143 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 12.

From the NOAA station Spearfish, SD — 4 miles away, elevation 3,632 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 57783

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 31 – Apr 14
SpinachSow outdoors · Mar 31 – Apr 21
Broccoli, cabbageStart indoors · Mar 3 – Mar 17
Broccoli, cabbageTransplant · Apr 21 – May 5
Onion setsPlant outdoors · Apr 14 – Apr 28
PotatoesPlant outdoors · Apr 21 – May 5
LettuceSow outdoors · Apr 14 – Apr 28
Carrots, beetsSow outdoors · Apr 21 – May 5
TomatoesStart indoors · Mar 17 – Mar 31
TomatoesTransplant · May 19 – Jun 2
Peppers, eggplantStart indoors · Mar 3 – Mar 17
Peppers, eggplantTransplant · May 26 – Jun 9
BeansSow outdoors · May 19 – Jun 2
Sweet cornSow outdoors · May 19 – Jun 2
Cucumbers, squashSow outdoors · May 19 – Jun 2
Fall lettuce, spinachSow outdoors · Aug 7 – Aug 21
GarlicPlant cloves · Sep 18 – Oct 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 12) and first fall frost (Oct 2) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 57783 came on Mar 12 — 29 days earlier than the 1991–2020 average (Apr 10).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 5b in South Dakota

458 plants native to the lower 48 states, recorded in South Dakota, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 23

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblack maple100 ft · blooms late spring · low shade tolerance · to −47 °Fblack walnut100 ft · blooms late spring · high shade tolerance · to −28 °F

Shrubs 70

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fbeaked hazelnut15 ft · blooms early spring · low shade tolerance · to −47 °F

Wildflowers & perennials 206

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °F

Grasses 146

Alaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 5

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Spearfish, SD.

Soil in Spearfish, SD

The soil mapped at the center of ZIP 57783 is Opechekahta — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer
pH4.7strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter55%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Opechekahta-Citivar-Schaeferville complex, 20 to 60 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 57783; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Spearfish, SD

Summer high84 °Faverage high, July
Winter low16 °Faverage low, January
Hot days26days a year at 90 °F or more
Freezing nights144nights a year at 32 °F or less
Growing degree days2,333base 50 °F — the season’s usable heat
Longest day15 h 33 mindaylight on June 21
Shortest day8 h 50 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation21.4 inper year, rain and melted snow
Snowfall71 inper year; 69 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 36 °F, low 16 °F 36°16° JanFebruary: average high 37 °F, low 16 °F 37°16° FebMarch: average high 46 °F, low 24 °F 46°24° MarApril: average high 55 °F, low 32 °F 55°32° AprMay: average high 64 °F, low 42 °F 64°42° MayJune: average high 75 °F, low 51 °F 75°51° JunJuly: average high 84 °F, low 58 °F 84°58° JulAugust: average high 83 °F, low 56 °F 83°56° AugSeptember: average high 74 °F, low 48 °F 74°48° SepOctober: average high 58 °F, low 35 °F 58°35° OctNovember: average high 46 °F, low 26 °F 46°26° NovDecember: average high 37 °F, low 18 °F 37°18° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.60 in precipitation, 8.2 in snowfall 0.6❄8 JanFebruary: 0.91 in precipitation, 12.7 in snowfall 0.9❄13 FebMarch: 1.19 in precipitation, 12 in snowfall 1.2❄12 MarApril: 2.23 in precipitation, 8.5 in snowfall 2.2❄9 AprMay: 3.72 in precipitation, 2.3 in snowfall 3.7❄2 MayJune: 3.51 in precipitation 3.5 JunJuly: 2.35 in precipitation 2.4 JulAugust: 1.88 in precipitation 1.9 AugSeptember: 1.56 in precipitation, 0.1 in snowfall 1.6 SepOctober: 2.04 in precipitation, 5.5 in snowfall 2.0❄6 OctNovember: 0.70 in precipitation, 6.3 in snowfall 0.7❄6 NovDecember: 0.72 in precipitation, 14.9 in snowfall 0.7❄15 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Spearfish, SD (4 mi away); precipitation: Spearfish, SD (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

7 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

827125a
Beulah, WY · 11 mi
577795b
Saint Onge, SD · 11 mi
577545a
Lead, SD · 14 mi
577325a
Deadwood, SD · 15 mi
577935a
Whitewood, SD · 18 mi
827294b
Sundance, WY · 22 mi
577595a
Nemo, SD · 24 mi
827105a
Aladdin, WY · 25 mi

South Dakota planting zones →

Questions about 57783

What planting zone is ZIP code 57783?

ZIP code 57783 (Spearfish, SD) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Spearfish, SD?

The median last spring frost (32 °F) near 57783 is May 12; after May 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Spearfish station.

When is the first frost in Spearfish, SD?

The median first fall frost near 57783 is October 2, giving a median frost-free growing season of 143 days.

When should I plant tomatoes in 57783?

Start tomato seeds indoors around Mar 17 – Mar 31 and set transplants outside around May 19 – Jun 2, one to three weeks after the median last frost.

How much rain and snow does 57783 get?

About 21.4 inches of precipitation a year and 71 inches of snowfall (NOAA 1991–2020 normals, Spearfish station).

How hot do summers get in Spearfish, SD?

The average high peaks at 84 °F in July, with about 26 days a year at 90 °F or more.

What kind of soil does 57783 have?

The USDA soil survey maps Opechekahta at the center of ZIP 57783: moderately decomposed plant material, well drained, pH about 4.7 (strongly acidic).

Did spring come early in Spearfish, SD in 2026?

Spring leaf-out near 57783 came on Mar 12 in 2026, 29 days earlier than the 1991–2020 average (Apr 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Spearfish, SD?

Long-day onions: the longest day near 57783 is 15 h 33 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 57783 change?

Yes. The 2012 USDA map put 57783 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.