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

Planting zone for 83101 — Kemmerer, WY

ZIP code 83101 (Kemmerer, Lincoln County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is June 9 and the first fall frost September 4.

Where ZIP 83101 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 9

First frostSep 4

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 Kemmerer, 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 Kemmerer, WY

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostJune 9median — 50% chance of a later frost

Safe for tender plantsJune 27only 10% chance of frost after

First fall frostSeptember 4median — 10% chance by Aug 21

Growing season84 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 24 and returns around September 15.

From the NOAA station La Barge, WY — 27 miles away, elevation 6,598 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 83101

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 28 – May 12

SpinachSow outdoors · Apr 28 – May 19

Broccoli, cabbageStart indoors · Mar 31 – Apr 14

Broccoli, cabbageTransplant · May 19 – Jun 2

Onion setsPlant outdoors · May 12 – May 26

PotatoesPlant outdoors · May 19 – Jun 2

LettuceSow outdoors · May 12 – May 26

Carrots, beetsSow outdoors · May 19 – Jun 2

TomatoesStart indoors · Apr 14 – Apr 28

TomatoesTransplant · Jun 16 – Jun 30

Peppers, eggplantStart indoors · Mar 31 – Apr 14

Peppers, eggplantTransplant · Jun 23 – Jul 7

BeansSow outdoors · Jun 16 – Jun 30

Sweet cornSow outdoors · Jun 16 – Jun 30

Cucumbers, squashSow outdoors · Jun 16 – Jun 30

Fall lettuce, spinachSow outdoors · Jul 10 – Jul 24

GarlicPlant cloves · Aug 21 – Sep 25

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 9) and first fall frost (Sep 4) 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 83101 came on Apr 23 — 15 days earlier than the 1991–2020 average (May 8).

average
May 82026
Apr 23

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 Kemmerer, WY.

Soil in Kemmerer, WY

The soil mapped at the center of ZIP 83101 is Tusler — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding

pH6.4slightly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Tusler-Galedor-Fleak complex, 1 to 8 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 83101; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kemmerer, 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 14 mindaylight on June 21

Shortest day9 h 07 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

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Kemmerer 2n, WY (11 mi away); precipitation: Kemmerer 2n, WY (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

831214b

Frontier, WY · 9 mi

831164b

Diamondville, WY · 15 mi

831244b

Opal, WY · 19 mi

831144a

Cokeville, WY · 23 mi

Wyoming planting zones →

Questions about 83101

What planting zone is ZIP code 83101?

ZIP code 83101 (Kemmerer, 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 Kemmerer, WY?

The median last spring frost (32 °F) near 83101 is June 9; after June 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, La Barge station.

When is the first frost in Kemmerer, WY?

The median first fall frost near 83101 is September 4, giving a median frost-free growing season of 84 days.

When should I plant tomatoes in 83101?

Start tomato seeds indoors around Apr 14 – Apr 28 and set transplants outside around Jun 16 – Jun 30, one to three weeks after the median last frost.

How much rain and snow does 83101 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 Kemmerer, 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 83101 have?

The USDA soil survey maps Tusler at the center of ZIP 83101: fine sandy loam, well drained, pH about 6.4 (slightly acidic).

Did spring come early in Kemmerer, WY in 2026?

Spring leaf-out near 83101 came on Apr 23 in 2026, 15 days earlier than the 1991–2020 average (May 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Kemmerer, WY?

Long-day onions: the longest day near 83101 is 15 h 14 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 83101 change?

Yes. The 2012 USDA map put 83101 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.