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

Planting zone for 81081 — Trinchera, CO

ZIP code 81081 (Trinchera, Las Animas County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 21 and the first fall frost September 29.

Where ZIP 81081 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostMay 21
First frostSep 29
2012 zone6a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Trinchera, 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 Trinchera, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 21median — 50% chance of a later frost
Safe for tender plantsJune 4only 10% chance of frost after
First fall frostSeptember 29median — 10% chance by Sep 16
Growing season128 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 10 and returns around October 7.

From the NOAA station Lake Maloya, NM — 14 miles away, elevation 7,402 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 81081

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 9 – Apr 23
SpinachSow outdoors · Apr 9 – Apr 30
Broccoli, cabbageStart indoors · Mar 12 – Mar 26
Broccoli, cabbageTransplant · Apr 30 – May 14
Onion setsPlant outdoors · Apr 23 – May 7
PotatoesPlant outdoors · Apr 30 – May 14
LettuceSow outdoors · Apr 23 – May 7
Carrots, beetsSow outdoors · Apr 30 – May 14
TomatoesStart indoors · Mar 26 – Apr 9
TomatoesTransplant · May 28 – Jun 11
Peppers, eggplantStart indoors · Mar 12 – Mar 26
Peppers, eggplantTransplant · Jun 4 – Jun 18
BeansSow outdoors · May 28 – Jun 11
Sweet cornSow outdoors · May 28 – Jun 11
Cucumbers, squashSow outdoors · May 28 – Jun 11
Fall lettuce, spinachSow outdoors · Aug 4 – Aug 18
GarlicPlant cloves · Sep 15 – Oct 20
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 21) and first fall frost (Sep 29) 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 81081 came on Feb 26 — 18 days earlier than the 1991–2020 average (Mar 16).

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 6a in Colorado

563 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. 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 251

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 167

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 Trinchera, CO.

Soil in Trinchera, CO

The soil mapped at the center of ZIP 81081 is Manzanst — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH8.0alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Manzanst silty clay loam, cool, 0 to 3 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 81081; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Trinchera, CO

Summer high78 °Faverage high, July
Winter low11 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights205nights a year at 32 °F or less
Growing degree days1,431base 50 °F — the season’s usable heat
Longest day14 h 43 mindaylight on June 21
Shortest day9 h 37 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation21.4 inper year, rain and melted snow
Snowfall89 inper year

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 42 °F, low 11 °F 42°11° JanFebruary: average high 43 °F, low 12 °F 43°12° FebMarch: average high 50 °F, low 20 °F 50°20° MarApril: average high 57 °F, low 27 °F 57°27° AprMay: average high 66 °F, low 36 °F 66°36° MayJune: average high 75 °F, low 44 °F 75°44° JunJuly: average high 78 °F, low 49 °F 78°49° JulAugust: average high 76 °F, low 48 °F 76°48° AugSeptember: average high 71 °F, low 41 °F 71°41° SepOctober: average high 60 °F, low 31 °F 60°31° OctNovember: average high 50 °F, low 21 °F 50°21° NovDecember: average high 42 °F, low 13 °F 42°13° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.86 in precipitation, 13.4 in snowfall 0.9❄13 JanFebruary: 0.87 in precipitation, 13 in snowfall 0.9❄13 FebMarch: 1.80 in precipitation, 18.3 in snowfall 1.8❄18 MarApril: 2.01 in precipitation, 11 in snowfall 2.0❄11 AprMay: 2.02 in precipitation, 1.6 in snowfall 2.0❄2 MayJune: 2.02 in precipitation 2.0 JunJuly: 3.44 in precipitation 3.4 JulAugust: 2.95 in precipitation 3.0 AugSeptember: 1.92 in precipitation, 0.2 in snowfall 1.9 SepOctober: 1.57 in precipitation, 5.2 in snowfall 1.6❄5 OctNovember: 1.06 in precipitation, 11 in snowfall 1.1❄11 NovDecember: 0.93 in precipitation, 15.6 in snowfall 0.9❄16 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Lake Maloya, NM (14 mi away); precipitation: Lake Maloya, NM (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.

810826a
Trinidad, CO · 16 mi
810466a
Hoehne, CO · 20 mi
884145b
Capulin, NM · 21 mi
877406a
Raton, NM · 24 mi
810276a
Branson, CO · 27 mi
810246a
Boncarbo, CO · 33 mi
810596a
Model, CO · 35 mi
884186b
Des Moines, NM · 36 mi

Colorado planting zones →

Questions about 81081

What planting zone is ZIP code 81081?

ZIP code 81081 (Trinchera, CO) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Trinchera, CO?

The median last spring frost (32 °F) near 81081 is May 21; after June 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lake Maloya station.

When is the first frost in Trinchera, CO?

The median first fall frost near 81081 is September 29, giving a median frost-free growing season of 128 days.

When should I plant tomatoes in 81081?

Start tomato seeds indoors around Mar 26 – Apr 9 and set transplants outside around May 28 – Jun 11, one to three weeks after the median last frost.

How much rain and snow does 81081 get?

About 21.4 inches of precipitation a year and 89 inches of snowfall (NOAA 1991–2020 normals, Lake Maloya station).

How hot do summers get in Trinchera, CO?

The average high peaks at 78 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 81081 have?

The USDA soil survey maps Manzanst at the center of ZIP 81081: silty clay loam, well drained, pH about 8.0 (alkaline).

Did spring come early in Trinchera, CO in 2026?

Spring leaf-out near 81081 came on Feb 26 in 2026, 18 days earlier than the 1991–2020 average (Mar 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Trinchera, CO?

Intermediate onions: the longest day near 81081 is 14 h 43 min, so day-neutral types bulb best; long-day varieties may not bulb fully.