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

Planting zone for 82834 — Buffalo, WY

ZIP code 82834 (Buffalo, Johnson County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 24 and the first fall frost September 21.

Where ZIP 82834 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 frostMay 24
First frostSep 21
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 Buffalo, 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 Buffalo, WY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 24median — 50% chance of a later frost
Safe for tender plantsJune 9only 10% chance of frost after
First fall frostSeptember 21median — 10% chance by Sep 7
Growing season118 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 12 and returns around September 30.

From the NOAA station Buffalo, WY — 7 miles away, elevation 4,639 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 82834

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 12 – Apr 26
SpinachSow outdoors · Apr 12 – May 3
Broccoli, cabbageStart indoors · Mar 15 – Mar 29
Broccoli, cabbageTransplant · May 3 – May 17
Onion setsPlant outdoors · Apr 26 – May 10
PotatoesPlant outdoors · May 3 – May 17
LettuceSow outdoors · Apr 26 – May 10
Carrots, beetsSow outdoors · May 3 – May 17
TomatoesStart indoors · Mar 29 – Apr 12
TomatoesTransplant · May 31 – Jun 14
Peppers, eggplantStart indoors · Mar 15 – Mar 29
Peppers, eggplantTransplant · Jun 7 – Jun 21
BeansSow outdoors · May 31 – Jun 14
Sweet cornSow outdoors · May 31 – Jun 14
Cucumbers, squashSow outdoors · May 31 – Jun 14
Fall lettuce, spinachSow outdoors · Jul 27 – Aug 10
GarlicPlant cloves · Sep 7 – Oct 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 24) and first fall frost (Sep 21) 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 82834 came on Mar 10 — 35 days earlier than the 1991–2020 average (Apr 14).

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 Buffalo, WY.

Soil in Buffalo, WY

The soil mapped at the center of ZIP 82834 is Bronec — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH7.4slightly alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Bronec-Trimad complex, 6 to 30 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 82834; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Buffalo, WY

Summer high83 °Faverage high, July
Winter low11 °Faverage low, January
Hot days19days a year at 90 °F or more
Freezing nights184nights a year at 32 °F or less
Growing degree days1,787base 50 °F — the season’s usable heat
Longest day15 h 31 mindaylight on June 21
Shortest day8 h 51 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation16.9 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 36 °F, low 11 °F 36°11° JanFebruary: average high 37 °F, low 12 °F 37°12° FebMarch: average high 47 °F, low 20 °F 47°20° MarApril: average high 53 °F, low 28 °F 53°28° AprMay: average high 62 °F, low 37 °F 62°37° MayJune: average high 73 °F, low 46 °F 73°46° JunJuly: average high 83 °F, low 53 °F 83°53° JulAugust: average high 82 °F, low 51 °F 82°51° AugSeptember: average high 72 °F, low 42 °F 72°42° SepOctober: average high 57 °F, low 30 °F 57°30° OctNovember: average high 45 °F, low 19 °F 45°19° NovDecember: average high 36 °F, low 11 °F 36°11° Dec

Precipitation by month inches

0″1″2″3″4″January: 0.45 in precipitation 0.5 JanFebruary: 0.74 in precipitation 0.7 FebMarch: 0.99 in precipitation 1.0 MarApril: 2.03 in precipitation 2.0 AprMay: 3.62 in precipitation 3.6 MayJune: 2.33 in precipitation 2.3 JunJuly: 1.60 in precipitation 1.6 JulAugust: 0.94 in precipitation 0.9 AugSeptember: 1.53 in precipitation 1.5 SepOctober: 1.36 in precipitation 1.4 OctNovember: 0.71 in precipitation 0.7 NovDecember: 0.59 in precipitation 0.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Buffalo, WY (7 mi away); precipitation: Buffalo 4.1 Ssw, WY (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

828405a
Saddlestring, WY · 18 mi
828425a
Story, WY · 24 mi
828325a
Banner, WY · 24 mi
828335a
Big Horn, WY · 32 mi
828455a
Wyarno, WY · 34 mi
828355a
Clearmont, WY · 39 mi
828374b
Leiter, WY · 39 mi
828015a
Sheridan, WY · 40 mi

Wyoming planting zones →

Questions about 82834

What planting zone is ZIP code 82834?

ZIP code 82834 (Buffalo, 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 Buffalo, WY?

The median last spring frost (32 °F) near 82834 is May 24; after June 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Buffalo station.

When is the first frost in Buffalo, WY?

The median first fall frost near 82834 is September 21, giving a median frost-free growing season of 118 days.

When should I plant tomatoes in 82834?

Start tomato seeds indoors around Mar 29 – Apr 12 and set transplants outside around May 31 – Jun 14, one to three weeks after the median last frost.

How much rain and snow does 82834 get?

About 16.9 inches of precipitation a year (NOAA 1991–2020 normals, Buffalo 4.1 Ssw station).

How hot do summers get in Buffalo, WY?

The average high peaks at 83 °F in July, with about 19 days a year at 90 °F or more.

What kind of soil does 82834 have?

The USDA soil survey maps Bronec at the center of ZIP 82834: sandy loam, well drained, pH about 7.4 (slightly alkaline).

Did spring come early in Buffalo, WY in 2026?

Spring leaf-out near 82834 came on Mar 10 in 2026, 35 days earlier than the 1991–2020 average (Apr 14), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Buffalo, WY?

Long-day onions: the longest day near 82834 is 15 h 31 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 82834 change?

Yes. The 2012 USDA map put 82834 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.