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

Planting zone for 81230 — Gunnison, CO

ZIP code 81230 (Gunnison, Gunnison County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is June 21 and the first fall frost September 5.

Where ZIP 81230 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostJun 21

First frostSep 5

2012 zone4a

Was 4a on the 2012 map — 1.5 zones warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Gunnison, 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 Gunnison, CO

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 21median — 50% chance of a later frost

Safe for tender plantsJuly 7only 10% chance of frost after

First fall frostSeptember 5median — 10% chance by Aug 21

Growing season74 daysfrost-free, median

A hard freeze (28 °F) usually ends around June 7 and returns around September 16.

From the NOAA station Cochetopa Creek, CO — 11 miles away, elevation 8,006 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 81230

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · May 10 – May 24

SpinachSow outdoors · May 10 – May 31

Broccoli, cabbageStart indoors · Apr 12 – Apr 26

Broccoli, cabbageTransplant · May 31 – Jun 14

Onion setsPlant outdoors · May 24 – Jun 7

PotatoesPlant outdoors · May 31 – Jun 14

LettuceSow outdoors · May 24 – Jun 7

Carrots, beetsSow outdoors · May 31 – Jun 14

TomatoesStart indoors · Apr 26 – May 10

TomatoesTransplant · Jun 28 – Jul 12

Peppers, eggplantStart indoors · Apr 12 – Apr 26

Peppers, eggplantTransplant · Jul 5 – Jul 19

BeansSow outdoors · Jun 28 – Jul 12

Sweet cornSow outdoors · Jun 28 – Jul 12

Cucumbers, squashSow outdoors · Jun 28 – Jul 12

Fall lettuce, spinachSow outdoors · Jul 11 – Jul 25

GarlicPlant cloves · Aug 22 – Sep 26

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 21) and first fall frost (Sep 5) 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 81230 came on Apr 1 — 33 days earlier than the 1991–2020 average (May 4).

average
May 42026
Apr 1

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 5b in Colorado

546 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. 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 Gunnison, CO.

Soil in Gunnison, CO

The soil mapped at the center of ZIP 81230 is Lucky — gravelly sandy loam, well drained.

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

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Lucky-Beenom, exposed complex, 5 to 45 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 81230; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Gunnison, CO

Summer high80 °Faverage high, July

Winter low−6 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights247nights a year at 32 °F or less

Growing degree days1,028base 50 °F — the season’s usable heat

Longest day14 h 51 mindaylight on June 21

Shortest day9 h 29 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation17.1 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: Gunnison 3sw, CO (9 mi away); precipitation: Powderhorn 4.4 Nne, CO (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

812435b

Powderhorn, CO · 16 mi

812394b

Parlin, CO · 21 mi

812375a

Ohio City, CO · 24 mi

Crested Butte, CO · 34 mi

Colorado planting zones →

Questions about 81230

What planting zone is ZIP code 81230?

ZIP code 81230 (Gunnison, CO) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Gunnison, CO?

The median last spring frost (32 °F) near 81230 is June 21; after July 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cochetopa Creek station.

When is the first frost in Gunnison, CO?

The median first fall frost near 81230 is September 5, giving a median frost-free growing season of 74 days.

When should I plant tomatoes in 81230?

Start tomato seeds indoors around Apr 26 – May 10 and set transplants outside around Jun 28 – Jul 12, one to three weeks after the median last frost.

How much rain and snow does 81230 get?

About 17.1 inches of precipitation a year (NOAA 1991–2020 normals, Powderhorn 4.4 Nne station).

How hot do summers get in Gunnison, CO?

The average high peaks at 80 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 81230 have?

The USDA soil survey maps Lucky at the center of ZIP 81230: gravelly sandy loam, well drained, pH about 6.7 (neutral).

Did spring come early in Gunnison, CO in 2026?

Spring leaf-out near 81230 came on Apr 1 in 2026, 33 days earlier than the 1991–2020 average (May 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Gunnison, CO?

Intermediate onions: the longest day near 81230 is 14 h 51 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 81230 change?

Yes. The 2012 USDA map put 81230 in zone 4a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.