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

Planting zone for 80434 — Cowdrey, CO

ZIP code 80434 (Cowdrey, Jackson County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is June 2 and the first fall frost September 19.

Where ZIP 80434 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostJun 2

First frostSep 19

2012 zone4a

Was 4a 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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Cowdrey, CO…

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 Cowdrey, CO

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 — 29 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 80434

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 80434 came on Apr 17 — 20 days earlier than the 1991–2020 average (May 7).

average
May 72026
Apr 17

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 4b in Colorado

484 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. 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 Cowdrey, CO.

Soil in Cowdrey, CO

The soil mapped at the center of ZIP 80434 is Bangston — fine sand, somewhat excessively drained.

TextureFine sanddrains and warms fast; dries out and needs more feeding

pH7.0neutral; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter2%moderate

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Bangston fine sand, 1 to 10 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 80434; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cowdrey, CO

Summer high76 °Faverage high, July

Winter low2 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights258nights a year at 32 °F or less

Growing degree days546base 50 °F — the season’s usable heat

Longest day15 h 07 mindaylight on June 21

Shortest day9 h 14 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation12.1 inper year, rain and melted snow

Snowfall67 inper year; 115 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Walden, CO (11 mi away); precipitation: Walden, CO (11 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.

Encampment, WY · 31 mi

Centennial, WY · 32 mi

804285a

Clark, CO · 34 mi

Colorado planting zones →

Questions about 80434

What planting zone is ZIP code 80434?

ZIP code 80434 (Cowdrey, CO) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Cowdrey, CO?

The median last spring frost (32 °F) near 80434 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 Cowdrey, CO?

The median first fall frost near 80434 is September 19, giving a median frost-free growing season of 106 days.

When should I plant tomatoes in 80434?

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 80434 get?

About 12.1 inches of precipitation a year and 67 inches of snowfall (NOAA 1991–2020 normals, Walden station).

How hot do summers get in Cowdrey, CO?

The average high peaks at 76 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 80434 have?

The USDA soil survey maps Bangston at the center of ZIP 80434: fine sand, somewhat excessively drained, pH about 7.0 (neutral).

Did spring come early in Cowdrey, CO in 2026?

Spring leaf-out near 80434 came on Apr 17 in 2026, 20 days earlier than the 1991–2020 average (May 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cowdrey, CO?

Long-day onions: the longest day near 80434 is 15 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 80434 change?

Yes. The 2012 USDA map put 80434 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.