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

Planting zone for 81320 — Cahone, CO

ZIP code 81320 (Cahone, Dolores County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 11 and the first fall frost October 12.

Where ZIP 81320 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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostMay 11
First frostOct 12
2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Cahone, 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 Cahone, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 11median — 50% chance of a later frost
Safe for tender plantsMay 25only 10% chance of frost after
First fall frostOctober 12median — 10% chance by Sep 29
Growing season152 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 21.

From the NOAA station Dove Creek, CO — 10 miles away, elevation 6,864 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 81320

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 30 – Apr 13
SpinachSow outdoors · Mar 30 – Apr 20
Broccoli, cabbageStart indoors · Mar 2 – Mar 16
Broccoli, cabbageTransplant · Apr 20 – May 4
Onion setsPlant outdoors · Apr 13 – Apr 27
PotatoesPlant outdoors · Apr 20 – May 4
LettuceSow outdoors · Apr 13 – Apr 27
Carrots, beetsSow outdoors · Apr 20 – May 4
TomatoesStart indoors · Mar 16 – Mar 30
TomatoesTransplant · May 18 – Jun 1
Peppers, eggplantStart indoors · Mar 2 – Mar 16
Peppers, eggplantTransplant · May 25 – Jun 8
BeansSow outdoors · May 18 – Jun 1
Sweet cornSow outdoors · May 18 – Jun 1
Cucumbers, squashSow outdoors · May 18 – Jun 1
Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31
GarlicPlant cloves · Sep 28 – Nov 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 11) and first fall frost (Oct 12) 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 81320 came on Mar 19 — 22 days earlier than the 1991–2020 average (Apr 10).

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 6b in Colorado

565 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Trees 28

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 °Fblack walnut100 ft · blooms late spring · high shade tolerance · to −28 °Fblack willow100 ft · blooms early spring · high shade tolerance · to −58 °Fblue spruce100 ft · blooms late spring · medium shade tolerance · to −38 °F

Shrubs 104

alderleaf 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 °FApache plume6 ft · blooms late spring · high shade tolerance · to −23 °F

Wildflowers & perennials 252

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine aster0.3 ft · blooms early summer · medium shade tolerance · to −28 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °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 168

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 4

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °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 Cahone, CO.

Soil in Cahone, CO

The soil mapped at the center of ZIP 81320 is Wauquie — very stony loam, well drained.

TextureVery stony loama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Wauquie-Dolcan-Rock outcrop complex, 25 to 80 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 81320; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cahone, CO

Summer high87 °Faverage high, July
Winter low17 °Faverage low, January
Hot days15days a year at 90 °F or more
Freezing nights160nights a year at 32 °F or less
Growing degree days2,492base 50 °F — the season’s usable heat
Longest day14 h 47 mindaylight on June 21
Shortest day9 h 33 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation15 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 38 °F, low 17 °F 38°17° JanFebruary: average high 42 °F, low 21 °F 42°21° FebMarch: average high 50 °F, low 28 °F 50°28° MarApril: average high 59 °F, low 32 °F 59°32° AprMay: average high 69 °F, low 41 °F 69°41° MayJune: average high 81 °F, low 52 °F 81°52° JunJuly: average high 87 °F, low 58 °F 87°58° JulAugust: average high 83 °F, low 56 °F 83°56° AugSeptember: average high 75 °F, low 49 °F 75°49° SepOctober: average high 62 °F, low 38 °F 62°38° OctNovember: average high 49 °F, low 27 °F 49°27° NovDecember: average high 38 °F, low 19 °F 38°19° Dec

Precipitation by month inches

0″1″2″January: 1.21 in precipitation 1.2 JanFebruary: 1.41 in precipitation 1.4 FebMarch: 1.07 in precipitation 1.1 MarApril: 0.94 in precipitation 0.9 AprMay: 1.19 in precipitation 1.2 MayJune: 0.37 in precipitation 0.4 JunJuly: 1.78 in precipitation 1.8 JulAugust: 1.82 in precipitation 1.8 AugSeptember: 1.40 in precipitation 1.4 SepOctober: 1.48 in precipitation 1.5 OctNovember: 1.06 in precipitation 1.1 NovDecember: 1.30 in precipitation 1.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Dove Creek, CO (10 mi away); precipitation: Yellow Jacket 2w, CO (14 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

813356b
Yellow Jacket, CO · 12 mi
813256b
Egnar, CO · 14 mi
813276b
Lewis, CO · 15 mi
813246b
Dove Creek, CO · 16 mi
813316b
Pleasant View, CO · 21 mi
814236a
Norwood, CO · 26 mi
813217a
Cortez, CO · 28 mi
814316b
Redvale, CO · 32 mi

Colorado planting zones →

Questions about 81320

What planting zone is ZIP code 81320?

ZIP code 81320 (Cahone, CO) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Cahone, CO?

The median last spring frost (32 °F) near 81320 is May 11; after May 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Dove Creek station.

When is the first frost in Cahone, CO?

The median first fall frost near 81320 is October 12, giving a median frost-free growing season of 152 days.

When should I plant tomatoes in 81320?

Start tomato seeds indoors around Mar 16 – Mar 30 and set transplants outside around May 18 – Jun 1, one to three weeks after the median last frost.

How much rain and snow does 81320 get?

About 15 inches of precipitation a year (NOAA 1991–2020 normals, Yellow Jacket 2w station).

How hot do summers get in Cahone, CO?

The average high peaks at 87 °F in July, with about 15 days a year at 90 °F or more.

What kind of soil does 81320 have?

The USDA soil survey maps Wauquie at the center of ZIP 81320: very stony loam, well drained, pH about 7.2 (neutral).

Did spring come early in Cahone, CO in 2026?

Spring leaf-out near 81320 came on Mar 19 in 2026, 22 days earlier than the 1991–2020 average (Apr 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cahone, CO?

Intermediate onions: the longest day near 81320 is 14 h 47 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 81320 change?

Yes. The 2012 USDA map put 81320 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.