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

Planting zone for 82426 — Greybull, WY

ZIP code 82426 (Greybull, Big Horn County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 11 and the first fall frost September 23.

Where ZIP 82426 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 11
First frostSep 23
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 Greybull, 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 Greybull, WY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 11median — 50% chance of a later frost
Safe for tender plantsMay 24only 10% chance of frost after
First fall frostSeptember 23median — 10% chance by Sep 11
Growing season133 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 3.

From the NOAA station Greybull, WY — 2 miles away, elevation 3,786 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 82426

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 30 – Apr 13
SpinachSow outdoors · Mar 30 – Apr 20
Broccoli, cabbageStart indoors · Mar 2 – Mar 16
Broccoli, cabbageTransplant · Apr 20 – May 4
Onion setsPlant outdoors · Apr 13 – Apr 27
PotatoesPlant outdoors · Apr 20 – May 4
LettuceSow outdoors · Apr 13 – Apr 27
Carrots, beetsSow outdoors · Apr 20 – May 4
TomatoesStart indoors · Mar 16 – Mar 30
TomatoesTransplant · May 18 – Jun 1
Peppers, eggplantStart indoors · Mar 2 – Mar 16
Peppers, eggplantTransplant · May 25 – Jun 8
BeansSow outdoors · May 18 – Jun 1
Sweet cornSow outdoors · May 18 – Jun 1
Cucumbers, squashSow outdoors · May 18 – Jun 1
Fall lettuce, spinachSow outdoors · Jul 29 – Aug 12
GarlicPlant cloves · Sep 9 – Oct 14
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 11) and first fall frost (Sep 23) 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 82426 came on Mar 21 — 17 days earlier than the 1991–2020 average (Apr 7).

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 Greybull, WY.

Soil in Greybull, WY

The soil mapped at the center of ZIP 82426 is Emblem — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH8.0alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Emblem-Garland complex, 0 to 10 percent slopes -- Draft.

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 82426; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Greybull, WY

Summer high91 °Faverage high, July
Winter low2 °Faverage low, January
Hot days49days a year at 90 °F or more
Freezing nights185nights a year at 32 °F or less
Growing degree days2,432base 50 °F — the season’s usable heat
Longest day15 h 33 mindaylight on June 21
Shortest day8 h 49 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation7.2 inper year, rain and melted snow
Snowfall19 inper year; 61 days with snow on the ground

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 30 °F, low 2 °F 30°2° JanFebruary: average high 37 °F, low 9 °F 37°9° FebMarch: average high 52 °F, low 21 °F 52°21° MarApril: average high 61 °F, low 31 °F 61°31° AprMay: average high 71 °F, low 41 °F 71°41° MayJune: average high 81 °F, low 50 °F 81°50° JunJuly: average high 91 °F, low 55 °F 91°55° JulAugust: average high 88 °F, low 52 °F 88°52° AugSeptember: average high 77 °F, low 42 °F 77°42° SepOctober: average high 61 °F, low 30 °F 61°30° OctNovember: average high 45 °F, low 16 °F 45°16° NovDecember: average high 32 °F, low 6 °F 32°6° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 0.30 in precipitation, 3.3 in snowfall 0.3❄3 JanFebruary: 0.41 in precipitation, 6.2 in snowfall 0.4❄6 FebMarch: 0.19 in precipitation, 1.6 in snowfall 0.2❄2 MarApril: 0.58 in precipitation, 0.6 in snowfall 0.6❄1 AprMay: 1.37 in precipitation, 0.2 in snowfall 1.4 MayJune: 1.16 in precipitation 1.2 JunJuly: 0.47 in precipitation 0.5 JulAugust: 0.33 in precipitation 0.3 AugSeptember: 0.99 in precipitation, 0.2 in snowfall 1.0 SepOctober: 0.75 in precipitation, 0.7 in snowfall 0.8❄1 OctNovember: 0.43 in precipitation, 2.2 in snowfall 0.4❄2 NovDecember: 0.20 in precipitation, 4.2 in snowfall 0.2❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Greybull, WY (2 mi away); precipitation: Greybull, WY (2 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.

824104b
Basin, WY · 13 mi
824225a
Emblem, WY · 17 mi
824344b
Otto, WY · 17 mi
824415a
Shell, WY · 21 mi
824115a
Burlington, WY · 22 mi
824324b
Manderson, WY · 23 mi
824315a
Lovell, WY · 25 mi
824285a
Hyattville, WY · 27 mi

Wyoming planting zones →

Questions about 82426

What planting zone is ZIP code 82426?

ZIP code 82426 (Greybull, 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 Greybull, WY?

The median last spring frost (32 °F) near 82426 is May 11; after May 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Greybull station.

When is the first frost in Greybull, WY?

The median first fall frost near 82426 is September 23, giving a median frost-free growing season of 133 days.

When should I plant tomatoes in 82426?

Start tomato seeds indoors around Mar 16 – Mar 30 and set transplants outside around May 18 – Jun 1, one to three weeks after the median last frost.

How much rain and snow does 82426 get?

About 7.2 inches of precipitation a year and 19 inches of snowfall (NOAA 1991–2020 normals, Greybull station).

How hot do summers get in Greybull, WY?

The average high peaks at 91 °F in July, with about 49 days a year at 90 °F or more.

What kind of soil does 82426 have?

The USDA soil survey maps Emblem at the center of ZIP 82426: fine sandy loam, well drained, pH about 8.0 (alkaline).

Did spring come early in Greybull, WY in 2026?

Spring leaf-out near 82426 came on Mar 21 in 2026, 17 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Greybull, WY?

Long-day onions: the longest day near 82426 is 15 h 33 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).