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

Planting zone for 82331 — Saratoga, WY

ZIP code 82331 (Saratoga, Carbon County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is June 2 and the first fall frost September 12.

Where ZIP 82331 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 2
First frostSep 12
2012 zone4b

Was 4b on the 2012 map — half a zone warmer now. 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 Saratoga, 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 Saratoga, WY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 2median — 50% chance of a later frost
Safe for tender plantsJune 21only 10% chance of frost after
First fall frostSeptember 12median — 10% chance by Aug 12
Growing season101 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 15 and returns around September 29.

From the NOAA station Saratoga, WY — 4 miles away, elevation 6,792 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 82331

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 21 – May 5
SpinachSow outdoors · Apr 21 – May 12
Broccoli, cabbageStart indoors · Mar 24 – Apr 7
Broccoli, cabbageTransplant · May 12 – May 26
Onion setsPlant outdoors · May 5 – May 19
PotatoesPlant outdoors · May 12 – May 26
LettuceSow outdoors · May 5 – May 19
Carrots, beetsSow outdoors · May 12 – May 26
TomatoesStart indoors · Apr 7 – Apr 21
TomatoesTransplant · Jun 9 – Jun 23
Peppers, eggplantStart indoors · Mar 24 – Apr 7
Peppers, eggplantTransplant · Jun 16 – Jun 30
BeansSow outdoors · Jun 9 – Jun 23
Sweet cornSow outdoors · Jun 9 – Jun 23
Cucumbers, squashSow outdoors · Jun 9 – Jun 23
Fall lettuce, spinachSow outdoors · Jul 18 – Aug 1
GarlicPlant cloves · Aug 29 – Oct 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 2) and first fall frost (Sep 12) 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 82331 came on Mar 26 — 29 days earlier than the 1991–2020 average (Apr 24).

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 Saratoga, WY.

Soil in Saratoga, WY

The soil mapped at the center of ZIP 82331 is Canburn — loam, somewhat poorly drained.

TextureLoama good balance for most vegetables
pH6.6neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Canburn loam, 0 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 82331; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Saratoga, WY

Summer high84 °Faverage high, July
Winter low12 °Faverage low, December
Hot days5days a year at 90 °F or more
Freezing nights195nights a year at 32 °F or less
Growing degree days1,580base 50 °F — the season’s usable heat
Longest day15 h 10 mindaylight on June 21
Shortest day9 h 11 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation14.4 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 34 °F, low 14 °F 34°14° JanFebruary: average high 37 °F, low 15 °F 37°15° FebMarch: average high 47 °F, low 23 °F 47°23° MarApril: average high 56 °F, low 29 °F 56°29° AprMay: average high 66 °F, low 36 °F 66°36° MayJune: average high 77 °F, low 42 °F 77°42° JunJuly: average high 84 °F, low 51 °F 84°51° JulAugust: average high 81 °F, low 45 °F 81°45° AugSeptember: average high 72 °F, low 41 °F 72°41° SepOctober: average high 58 °F, low 31 °F 58°31° OctNovember: average high 44 °F, low 21 °F 44°21° NovDecember: average high 34 °F, low 12 °F 34°12° Dec

Precipitation by month inches

0″1″2″3″January: 0.69 in precipitation 0.7 JanFebruary: 0.83 in precipitation 0.8 FebMarch: 1.23 in precipitation 1.2 MarApril: 1.04 in precipitation 1.0 AprMay: 2.06 in precipitation 2.1 MayJune: 1.41 in precipitation 1.4 JunJuly: 1.00 in precipitation 1.0 JulAugust: 1.11 in precipitation 1.1 AugSeptember: 1.49 in precipitation 1.5 SepOctober: 1.82 in precipitation 1.8 OctNovember: 1.01 in precipitation 1.0 NovDecember: 0.76 in precipitation 0.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Saratoga, WY (4 mi away); precipitation: Saratoga 0.3 Ese (Usda Service, WY (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

823255a
Encampment, WY · 17 mi
826154b
Shirley Basin, WY · 24 mi
823355a
Walcott, WY · 25 mi
823245a
Elk Mountain, WY · 27 mi
820555a
Centennial, WY · 29 mi
823325b
Savery, WY · 34 mi
804285a
Clark, CO · 39 mi
823345a
Sinclair, WY · 39 mi

Wyoming planting zones →

Questions about 82331

What planting zone is ZIP code 82331?

ZIP code 82331 (Saratoga, 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 Saratoga, WY?

The median last spring frost (32 °F) near 82331 is June 2; after June 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Saratoga station.

When is the first frost in Saratoga, WY?

The median first fall frost near 82331 is September 12, giving a median frost-free growing season of 101 days.

When should I plant tomatoes in 82331?

Start tomato seeds indoors around Apr 7 – Apr 21 and set transplants outside around Jun 9 – Jun 23, one to three weeks after the median last frost.

How much rain and snow does 82331 get?

About 14.4 inches of precipitation a year (NOAA 1991–2020 normals, Saratoga 0.3 Ese (Usda Service station).

How hot do summers get in Saratoga, WY?

The average high peaks at 84 °F in July, with about 5 days a year at 90 °F or more.

What kind of soil does 82331 have?

The USDA soil survey maps Canburn at the center of ZIP 82331: loam, somewhat poorly drained, pH about 6.6 (neutral).

Did spring come early in Saratoga, WY in 2026?

Spring leaf-out near 82331 came on Mar 26 in 2026, 29 days earlier than the 1991–2020 average (Apr 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Saratoga, WY?

Long-day onions: the longest day near 82331 is 15 h 10 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 82331 change?

Yes. The 2012 USDA map put 82331 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.