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

Planting zone for 82729 — Sundance, WY

ZIP code 82729 (Sundance, Crook County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 21 and the first fall frost September 25.

Where ZIP 82729 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 21
First frostSep 25
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 Sundance, WY…

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 Sundance, WY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 21median — 50% chance of a later frost
Safe for tender plantsJune 5only 10% chance of frost after
First fall frostSeptember 25median — 10% chance by Sep 7
Growing season124 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 9 and returns around October 4.

From the NOAA station Sundance, WY — 3 miles away, elevation 4,695 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 82729

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 9 – Apr 23
SpinachSow outdoors · Apr 9 – Apr 30
Broccoli, cabbageStart indoors · Mar 12 – Mar 26
Broccoli, cabbageTransplant · Apr 30 – May 14
Onion setsPlant outdoors · Apr 23 – May 7
PotatoesPlant outdoors · Apr 30 – May 14
LettuceSow outdoors · Apr 23 – May 7
Carrots, beetsSow outdoors · Apr 30 – May 14
TomatoesStart indoors · Mar 26 – Apr 9
TomatoesTransplant · May 28 – Jun 11
Peppers, eggplantStart indoors · Mar 12 – Mar 26
Peppers, eggplantTransplant · Jun 4 – Jun 18
BeansSow outdoors · May 28 – Jun 11
Sweet cornSow outdoors · May 28 – Jun 11
Cucumbers, squashSow outdoors · May 28 – Jun 11
Fall lettuce, spinachSow outdoors · Jul 31 – Aug 14
GarlicPlant cloves · Sep 11 – Oct 16
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 21) and first fall frost (Sep 25) 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 82729 came on Mar 27 — 23 days earlier than the 1991–2020 average (Apr 19).

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 Wyoming

495 plants native to the lower 48 states, recorded in Wyoming, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. Each links to its USDA PLANTS profile.

Trees 22

American 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 °Fblue spruce100 ft · blooms late spring · medium shade tolerance · to −38 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °FDouglas-fir200 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 83

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °F

Wildflowers & perennials 226

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 alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °F

Grasses 152

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 Meadow-Foxtail0.5 ft · blooms mid spring · medium shade tolerance · to −33 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °F

Vines 3

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °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 Sundance, WY.

Soil in Sundance, WY

The soil mapped at the center of ZIP 82729 is Nevee — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH7.8slightly alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Nevee silt loam, 1 to 6 percent slopes, eroded.

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 82729; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sundance, WY

Summer high82 °Faverage high, July
Winter low13 °Faverage low, January
Hot days19days a year at 90 °F or more
Freezing nights179nights a year at 32 °F or less
Growing degree days1,959base 50 °F — the season’s usable heat
Longest day15 h 32 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)
Precipitation20.4 inper year, rain and melted snow
Snowfall81 inper year; 92 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 33 °F, low 13 °F 33°13° JanFebruary: average high 34 °F, low 14 °F 34°14° FebMarch: average high 44 °F, low 22 °F 44°22° MarApril: average high 52 °F, low 29 °F 52°29° AprMay: average high 63 °F, low 39 °F 63°39° MayJune: average high 73 °F, low 49 °F 73°49° JunJuly: average high 82 °F, low 56 °F 82°56° JulAugust: average high 81 °F, low 54 °F 81°54° AugSeptember: average high 71 °F, low 45 °F 71°45° SepOctober: average high 56 °F, low 33 °F 56°33° OctNovember: average high 42 °F, low 22 °F 42°22° NovDecember: average high 33 °F, low 14 °F 33°14° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.82 in precipitation, 12.9 in snowfall 0.8❄13 JanFebruary: 0.89 in precipitation, 14.7 in snowfall 0.9❄15 FebMarch: 1.04 in precipitation, 10.3 in snowfall 1.0❄10 MarApril: 2.48 in precipitation, 13.2 in snowfall 2.5❄13 AprMay: 3.47 in precipitation, 1.5 in snowfall 3.5❄2 MayJune: 3.03 in precipitation 3.0 JunJuly: 2.48 in precipitation 2.5 JulAugust: 1.71 in precipitation 1.7 AugSeptember: 1.32 in precipitation, 0.9 in snowfall 1.3❄1 SepOctober: 1.71 in precipitation, 5.8 in snowfall 1.7❄6 OctNovember: 0.91 in precipitation, 9.8 in snowfall 0.9❄10 NovDecember: 0.51 in precipitation, 12.2 in snowfall 0.5❄12 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Sundance, WY (3 mi away); precipitation: Sundance, WY (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

827125a
Beulah, WY · 16 mi
827144b
Devils Tower, WY · 20 mi
577835b
Spearfish, SD · 22 mi
827105a
Aladdin, WY · 22 mi
827115a
Alva, WY · 24 mi
577545a
Lead, SD · 25 mi
827234b
Osage, WY · 26 mi
827214b
Moorcroft, WY · 27 mi

Wyoming planting zones →

Questions about 82729

What planting zone is ZIP code 82729?

ZIP code 82729 (Sundance, WY) 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 Sundance, WY?

The median last spring frost (32 °F) near 82729 is May 21; after June 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sundance station.

When is the first frost in Sundance, WY?

The median first fall frost near 82729 is September 25, giving a median frost-free growing season of 124 days.

When should I plant tomatoes in 82729?

Start tomato seeds indoors around Mar 26 – Apr 9 and set transplants outside around May 28 – Jun 11, one to three weeks after the median last frost.

How much rain and snow does 82729 get?

About 20.4 inches of precipitation a year and 81 inches of snowfall (NOAA 1991–2020 normals, Sundance station).

How hot do summers get in Sundance, WY?

The average high peaks at 82 °F in July, with about 19 days a year at 90 °F or more.

What kind of soil does 82729 have?

The USDA soil survey maps Nevee at the center of ZIP 82729: silt loam, well drained, pH about 7.8 (slightly alkaline).

Did spring come early in Sundance, WY in 2026?

Spring leaf-out near 82729 came on Mar 27 in 2026, 23 days earlier than the 1991–2020 average (Apr 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sundance, WY?

Long-day onions: the longest day near 82729 is 15 h 32 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).