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

Planting zone for 57735 — Edgemont, SD

ZIP code 57735 (Edgemont, Fall River County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 23 and the first fall frost September 20.

Where ZIP 57735 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.

Zone4b−25 to −20 °F
Coldest night−31.7 to −28.9 °C
Last frostMay 23
First frostSep 20
2012 zone4b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Edgemont, 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 Edgemont, SD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 23median — 50% chance of a later frost
Safe for tender plantsJune 7only 10% chance of frost after
First fall frostSeptember 20median — 10% chance by Sep 6
Growing season117 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 13 and returns around September 28.

From the NOAA station Edgemont, SD — 2 miles away, elevation 3,432 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 57735

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 11 – Apr 25
SpinachSow outdoors · Apr 11 – May 2
Broccoli, cabbageStart indoors · Mar 14 – Mar 28
Broccoli, cabbageTransplant · May 2 – May 16
Onion setsPlant outdoors · Apr 25 – May 9
PotatoesPlant outdoors · May 2 – May 16
LettuceSow outdoors · Apr 25 – May 9
Carrots, beetsSow outdoors · May 2 – May 16
TomatoesStart indoors · Mar 28 – Apr 11
TomatoesTransplant · May 30 – Jun 13
Peppers, eggplantStart indoors · Mar 14 – Mar 28
Peppers, eggplantTransplant · Jun 6 – Jun 20
BeansSow outdoors · May 30 – Jun 13
Sweet cornSow outdoors · May 30 – Jun 13
Cucumbers, squashSow outdoors · May 30 – Jun 13
Fall lettuce, spinachSow outdoors · Jul 26 – Aug 9
GarlicPlant cloves · Sep 6 – Oct 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 23) and first fall frost (Sep 20) 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 57735 came on Mar 18 — 15 days earlier than the 1991–2020 average (Apr 2).

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 4b in South Dakota

430 plants native to the lower 48 states, recorded in South Dakota, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. 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 65

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 191

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 138

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 Edgemont, SD.

Soil in Edgemont, SD

The soil mapped at the center of ZIP 57735 is Pierre — clay, well drained.

TextureClayholds water and nutrients; slow to drain and warm up
pH7.1neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Pierre-Grummit clays, 6 to 25 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 57735; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Edgemont, SD

Summer high89 °Faverage high, July
Winter low4 °Faverage low, January
Hot days45days a year at 90 °F or more
Freezing nights183nights a year at 32 °F or less
Growing degree days2,308base 50 °F — the season’s usable heat
Longest day15 h 24 mindaylight on June 21
Shortest day8 h 58 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation17.3 inper year, rain and melted snow

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 34 °F, low 4 °F 34°4° JanFebruary: average high 38 °F, low 8 °F 38°8° FebMarch: average high 50 °F, low 18 °F 50°18° MarApril: average high 59 °F, low 27 °F 59°27° AprMay: average high 69 °F, low 38 °F 69°38° MayJune: average high 80 °F, low 48 °F 80°48° JunJuly: average high 89 °F, low 55 °F 89°55° JulAugust: average high 87 °F, low 52 °F 87°52° AugSeptember: average high 78 °F, low 42 °F 78°42° SepOctober: average high 62 °F, low 27 °F 62°27° OctNovember: average high 47 °F, low 15 °F 47°15° NovDecember: average high 35 °F, low 5 °F 35°5° Dec

Precipitation by month inches

0″1″2″3″January: 0.61 in precipitation 0.6 JanFebruary: 0.67 in precipitation 0.7 FebMarch: 1.00 in precipitation 1.0 MarApril: 1.99 in precipitation 2.0 AprMay: 2.92 in precipitation 2.9 MayJune: 2.58 in precipitation 2.6 JunJuly: 2.15 in precipitation 2.1 JulAugust: 1.61 in precipitation 1.6 AugSeptember: 1.29 in precipitation 1.3 SepOctober: 1.42 in precipitation 1.4 OctNovember: 0.52 in precipitation 0.5 NovDecember: 0.58 in precipitation 0.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Edgemont, SD (2 mi away); precipitation: Edgemont 0.4 W, SD (within 1 mile). 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.

577475a
Hot Springs, SD · 18 mi
577735b
Pringle, SD · 25 mi
577305a
Custer, SD · 32 mi
577635a
Oelrichs, SD · 32 mi
822255a
Lusk, WY · 33 mi
827014b
Newcastle, WY · 41 mi
693675a
Whitney, NE · 42 mi
577515a
Keystone, SD · 45 mi

South Dakota planting zones →

Questions about 57735

What planting zone is ZIP code 57735?

ZIP code 57735 (Edgemont, SD) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Edgemont, SD?

The median last spring frost (32 °F) near 57735 is May 23; after June 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Edgemont station.

When is the first frost in Edgemont, SD?

The median first fall frost near 57735 is September 20, giving a median frost-free growing season of 117 days.

When should I plant tomatoes in 57735?

Start tomato seeds indoors around Mar 28 – Apr 11 and set transplants outside around May 30 – Jun 13, one to three weeks after the median last frost.

How much rain and snow does 57735 get?

About 17.3 inches of precipitation a year (NOAA 1991–2020 normals, Edgemont 0.4 W station).

How hot do summers get in Edgemont, SD?

The average high peaks at 89 °F in July, with about 45 days a year at 90 °F or more.

What kind of soil does 57735 have?

The USDA soil survey maps Pierre at the center of ZIP 57735: clay, well drained, pH about 7.1 (neutral).

Did spring come early in Edgemont, SD in 2026?

Spring leaf-out near 57735 came on Mar 18 in 2026, 15 days earlier than the 1991–2020 average (Apr 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Edgemont, SD?

Long-day onions: the longest day near 57735 is 15 h 24 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).