Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 82055 — Centennial, WY

ZIP code 82055 (Centennial, Albany 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 19.

Where ZIP 82055 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 19

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 Centennial, 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 Centennial, 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 20only 10% chance of frost after

First fall frostSeptember 19median — 10% chance by Sep 3

Growing season106 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 23 and returns around September 29.

From the NOAA station Centennial 1ne, WY — 7 miles away, elevation 8,170 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 82055

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 25 – Aug 8

GarlicPlant cloves · Sep 5 – Oct 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 2) and first fall frost (Sep 19) 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 82055 came on May 25 — 4 days earlier than the 1991–2020 average (May 29).

average
May 292026
May 25

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.

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 Centennial, WY.

Soil in Centennial, WY

The soil mapped at the center of ZIP 82055 is Endlich — very stony loam, well drained.

TextureVery stony loama good balance for most vegetables

pH5.0strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Endlich, very stony-Typic Cryaquepts association, 2 to 25 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 82055; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Centennial, WY

Summer high77 °Faverage high, July

Winter low12 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights225nights a year at 32 °F or less

Growing degree days1,108base 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)

Precipitation35.4 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Centennial 1ne, WY (7 mi away); precipitation: Brooklyn Lake, WY (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

823245a

Elk Mountain, WY · 22 mi

820704b

Laramie, WY · 24 mi

820834b

Rock River, WY · 28 mi

823315a

Saratoga, WY · 29 mi

823255a

Encampment, WY · 31 mi

Wyoming planting zones →

Questions about 82055

What planting zone is ZIP code 82055?

ZIP code 82055 (Centennial, 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 Centennial, WY?

The median last spring frost (32 °F) near 82055 is June 2; after June 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Centennial 1ne station.

When is the first frost in Centennial, WY?

The median first fall frost near 82055 is September 19, giving a median frost-free growing season of 106 days.

When should I plant tomatoes in 82055?

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 82055 get?

About 35.4 inches of precipitation a year (NOAA 1991–2020 normals, Brooklyn Lake station).

How hot do summers get in Centennial, WY?

The average high peaks at 77 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 82055 have?

The USDA soil survey maps Endlich at the center of ZIP 82055: very stony loam, well drained, pH about 5.0 (strongly acidic).

Did spring come early in Centennial, WY in 2026?

Spring leaf-out near 82055 came on May 25 in 2026, 4 days earlier than the 1991–2020 average (May 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Centennial, WY?

Long-day onions: the longest day near 82055 is 15 h 10 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 82055 change?

Yes. The 2012 USDA map put 82055 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.