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

Planting zone for 83124 — Opal, WY

ZIP code 83124 (Opal, Lincoln County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 25 and the first fall frost September 27.

Where ZIP 83124 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 25
First frostSep 27
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 Opal, 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 Opal, WY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 25median — 50% chance of a later frost
Safe for tender plantsJune 11only 10% chance of frost after
First fall frostSeptember 27median — 10% chance by Sep 14
Growing season124 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 8 and returns around October 5.

From the NOAA station Church Buttes Gas Plt, WY — 27 miles away, elevation 7,080 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 83124

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 13 – Apr 27
SpinachSow outdoors · Apr 13 – May 4
Broccoli, cabbageStart indoors · Mar 16 – Mar 30
Broccoli, cabbageTransplant · May 4 – May 18
Onion setsPlant outdoors · Apr 27 – May 11
PotatoesPlant outdoors · May 4 – May 18
LettuceSow outdoors · Apr 27 – May 11
Carrots, beetsSow outdoors · May 4 – May 18
TomatoesStart indoors · Mar 30 – Apr 13
TomatoesTransplant · Jun 1 – Jun 15
Peppers, eggplantStart indoors · Mar 16 – Mar 30
Peppers, eggplantTransplant · Jun 8 – Jun 22
BeansSow outdoors · Jun 1 – Jun 15
Sweet cornSow outdoors · Jun 1 – Jun 15
Cucumbers, squashSow outdoors · Jun 1 – Jun 15
Fall lettuce, spinachSow outdoors · Aug 2 – Aug 16
GarlicPlant cloves · Sep 13 – Oct 18
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 25) and first fall frost (Sep 27) 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 83124 came on Apr 8 — 23 days earlier than the 1991–2020 average (May 1).

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 Opal, WY.

Soil in Opal, WY

The soil mapped at the center of ZIP 83124 is Piezon — loam, well drained.

TextureLoama good balance for most vegetables
pH8.0alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Piezon-Lilsnake complex, 1 to 3 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 83124; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Opal, WY

Summer high83 °Faverage high, July
Winter low2 °Faverage low, January
Hot days4days a year at 90 °F or more
Freezing nights246nights a year at 32 °F or less
Growing degree days1,097base 50 °F — the season’s usable heat
Longest day15 h 13 mindaylight on June 21
Shortest day9 h 08 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation9.4 inper year, rain and melted snow
Snowfall50 inper year

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 31 °F, low 2 °F 31°2° JanFebruary: average high 34 °F, low 3 °F 34°3° FebMarch: average high 43 °F, low 13 °F 43°13° MarApril: average high 52 °F, low 21 °F 52°21° AprMay: average high 63 °F, low 31 °F 63°31° MayJune: average high 73 °F, low 37 °F 73°37° JunJuly: average high 83 °F, low 43 °F 83°43° JulAugust: average high 81 °F, low 41 °F 81°41° AugSeptember: average high 72 °F, low 32 °F 72°32° SepOctober: average high 57 °F, low 23 °F 57°23° OctNovember: average high 42 °F, low 13 °F 42°13° NovDecember: average high 31 °F, low 3 °F 31°3° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 0.69 in precipitation, 11.6 in snowfall 0.7❄12 JanFebruary: 0.60 in precipitation, 9.6 in snowfall 0.6❄10 FebMarch: 0.65 in precipitation, 6.1 in snowfall 0.7❄6 MarApril: 0.66 in precipitation, 3 in snowfall 0.7❄3 AprMay: 1.38 in precipitation, 1.4 in snowfall 1.4❄1 MayJune: 0.94 in precipitation, 0.1 in snowfall 0.9 JunJuly: 0.50 in precipitation 0.5 JulAugust: 0.86 in precipitation 0.9 AugSeptember: 0.97 in precipitation, 0.4 in snowfall 1.0 SepOctober: 0.84 in precipitation, 1.8 in snowfall 0.8❄2 OctNovember: 0.65 in precipitation, 6.2 in snowfall 0.7❄6 NovDecember: 0.67 in precipitation, 9.5 in snowfall 0.7❄10 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Kemmerer 2n, WY (12 mi away); precipitation: Kemmerer 2n, WY (12 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.

831164b
Diamondville, WY · 12 mi
831214b
Frontier, WY · 13 mi
831015a
Kemmerer, WY · 19 mi
829344b
Granger, WY · 19 mi
829295a
Little America, WY · 27 mi
829375a
Lyman, WY · 29 mi
831234a
La Barge, WY · 33 mi
829335b
Fort Bridger, WY · 35 mi

Wyoming planting zones →

Questions about 83124

What planting zone is ZIP code 83124?

ZIP code 83124 (Opal, 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 Opal, WY?

The median last spring frost (32 °F) near 83124 is May 25; after June 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Church Buttes Gas Plt station.

When is the first frost in Opal, WY?

The median first fall frost near 83124 is September 27, giving a median frost-free growing season of 124 days.

When should I plant tomatoes in 83124?

Start tomato seeds indoors around Mar 30 – Apr 13 and set transplants outside around Jun 1 – Jun 15, one to three weeks after the median last frost.

How much rain and snow does 83124 get?

About 9.4 inches of precipitation a year and 50 inches of snowfall (NOAA 1991–2020 normals, Kemmerer 2n station).

How hot do summers get in Opal, WY?

The average high peaks at 83 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 83124 have?

The USDA soil survey maps Piezon at the center of ZIP 83124: loam, well drained, pH about 8.0 (alkaline).

Did spring come early in Opal, WY in 2026?

Spring leaf-out near 83124 came on Apr 8 in 2026, 23 days earlier than the 1991–2020 average (May 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Opal, WY?

Long-day onions: the longest day near 83124 is 15 h 13 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).