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

Planting zone for 82944 — Robertson, WY

ZIP code 82944 (Robertson, Uinta County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is June 14 and the first fall frost September 9.

Where ZIP 82944 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostJun 14
First frostSep 9
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Robertson, 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 Robertson, WY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 14median — 50% chance of a later frost
Safe for tender plantsJuly 1only 10% chance of frost after
First fall frostSeptember 9median — 10% chance by Aug 23
Growing season84 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 30 and returns around September 20.

From the NOAA station Mtn View, WY — 12 miles away, elevation 6,802 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 82944

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · May 3 – May 17
SpinachSow outdoors · May 3 – May 24
Broccoli, cabbageStart indoors · Apr 5 – Apr 19
Broccoli, cabbageTransplant · May 24 – Jun 7
Onion setsPlant outdoors · May 17 – May 31
PotatoesPlant outdoors · May 24 – Jun 7
LettuceSow outdoors · May 17 – May 31
Carrots, beetsSow outdoors · May 24 – Jun 7
TomatoesStart indoors · Apr 19 – May 3
TomatoesTransplant · Jun 21 – Jul 5
Peppers, eggplantStart indoors · Apr 5 – Apr 19
Peppers, eggplantTransplant · Jun 28 – Jul 12
BeansSow outdoors · Jun 21 – Jul 5
Sweet cornSow outdoors · Jun 21 – Jul 5
Cucumbers, squashSow outdoors · Jun 21 – Jul 5
Fall lettuce, spinachSow outdoors · Jul 15 – Jul 29
GarlicPlant cloves · Aug 26 – Sep 30
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 14) and first fall frost (Sep 9) 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 82944 came on Apr 11 — 25 days earlier than the 1991–2020 average (May 6).

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 5a in Wyoming

542 plants native to the lower 48 states, recorded in Wyoming, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. 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 98

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 249

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 161

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 Robertson, WY.

Soil in Robertson, WY

The soil mapped at the center of ZIP 82944 is Morset — loam, well drained.

TextureLoama good balance for most vegetables
pH7.3neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of statewide importance, if irrigatedUSDA classification

Map unit: Morset-Teeler-Tibson complex, 1 to 6 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 82944; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Robertson, WY

Summer high80 °Faverage high, July
Winter low11 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights206nights a year at 32 °F or less
Growing degree days1,223base 50 °F — the season’s usable heat
Longest day15 h 08 mindaylight on June 21
Shortest day9 h 12 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation25.7 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 32 °F, low 11 °F 32°11° JanFebruary: average high 34 °F, low 11 °F 34°11° FebMarch: average high 44 °F, low 20 °F 44°20° MarApril: average high 52 °F, low 25 °F 52°25° AprMay: average high 63 °F, low 33 °F 63°33° MayJune: average high 73 °F, low 40 °F 73°40° JunJuly: average high 80 °F, low 47 °F 80°47° JulAugust: average high 78 °F, low 45 °F 78°45° AugSeptember: average high 70 °F, low 37 °F 70°37° SepOctober: average high 57 °F, low 28 °F 57°28° OctNovember: average high 41 °F, low 17 °F 41°17° NovDecember: average high 31 °F, low 11 °F 31°11° Dec

Precipitation by month inches

0″1″2″3″January: 2.25 in precipitation 2.3 JanFebruary: 2.14 in precipitation 2.1 FebMarch: 2.40 in precipitation 2.4 MarApril: 2.79 in precipitation 2.8 AprMay: 2.53 in precipitation 2.5 MayJune: 1.52 in precipitation 1.5 JunJuly: 1.74 in precipitation 1.7 JulAugust: 1.89 in precipitation 1.9 AugSeptember: 1.92 in precipitation 1.9 SepOctober: 2.16 in precipitation 2.2 OctNovember: 2.26 in precipitation 2.3 NovDecember: 2.11 in precipitation 2.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Mtn View, WY (12 mi away); precipitation: Hewinta, UT (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

829335b
Fort Bridger, WY · 10 mi
829395b
Mountain View, WY · 10 mi
829305a
Evanston, WY · 13 mi
829365b
Lonetree, WY · 17 mi
829375a
Lyman, WY · 19 mi
829315a
Evanston, WY · 24 mi
829385b
Mc Kinnon, WY · 31 mi
840315a
Hanna, UT · 34 mi

Wyoming planting zones →

Questions about 82944

What planting zone is ZIP code 82944?

ZIP code 82944 (Robertson, WY) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Robertson, WY?

The median last spring frost (32 °F) near 82944 is June 14; after July 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mtn View station.

When is the first frost in Robertson, WY?

The median first fall frost near 82944 is September 9, giving a median frost-free growing season of 84 days.

When should I plant tomatoes in 82944?

Start tomato seeds indoors around Apr 19 – May 3 and set transplants outside around Jun 21 – Jul 5, one to three weeks after the median last frost.

How much rain and snow does 82944 get?

About 25.7 inches of precipitation a year (NOAA 1991–2020 normals, Hewinta station).

How hot do summers get in Robertson, WY?

The average high peaks at 80 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 82944 have?

The USDA soil survey maps Morset at the center of ZIP 82944: loam, well drained, pH about 7.3 (neutral).

Did spring come early in Robertson, WY in 2026?

Spring leaf-out near 82944 came on Apr 11 in 2026, 25 days earlier than the 1991–2020 average (May 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Robertson, WY?

Long-day onions: the longest day near 82944 is 15 h 08 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).