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

Planting zone for 81141 — Manassa, CO

ZIP code 81141 (Manassa, Conejos County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 28 and the first fall frost September 21.

Where ZIP 81141 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 frostMay 28
First frostSep 21
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Manassa, 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 Manassa, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 28median — 50% chance of a later frost
Safe for tender plantsJune 11only 10% chance of frost after
First fall frostSeptember 21median — 10% chance by Sep 9
Growing season115 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 13 and returns around September 29.

From the NOAA station Manassa, CO — 2 miles away, elevation 7,694 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 81141

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 16 – Apr 30
SpinachSow outdoors · Apr 16 – May 7
Broccoli, cabbageStart indoors · Mar 19 – Apr 2
Broccoli, cabbageTransplant · May 7 – May 21
Onion setsPlant outdoors · Apr 30 – May 14
PotatoesPlant outdoors · May 7 – May 21
LettuceSow outdoors · Apr 30 – May 14
Carrots, beetsSow outdoors · May 7 – May 21
TomatoesStart indoors · Apr 2 – Apr 16
TomatoesTransplant · Jun 4 – Jun 18
Peppers, eggplantStart indoors · Mar 19 – Apr 2
Peppers, eggplantTransplant · Jun 11 – Jun 25
BeansSow outdoors · Jun 4 – Jun 18
Sweet cornSow outdoors · Jun 4 – Jun 18
Cucumbers, squashSow outdoors · Jun 4 – Jun 18
Fall lettuce, spinachSow outdoors · Jul 27 – Aug 10
GarlicPlant cloves · Sep 7 – Oct 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 28) and first fall frost (Sep 21) 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 81141 came on Mar 23 — 23 days earlier than the 1991–2020 average (Apr 15).

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 Colorado

532 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 27

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 95

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 239

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 159

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 3

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °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 Manassa, CO.

Soil in Manassa, CO

The soil mapped at the center of ZIP 81141 is Quamon — gravelly sandy loam, moderately well drained.

TextureGravelly sandy loamdrains and warms fast; dries out and needs more feeding
pH8.2alkaline; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter0.25%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Quamon-LaJara complex.

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 81141; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Manassa, CO

Summer high81 °Faverage high, July
Winter low5 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights206nights a year at 32 °F or less
Growing degree days1,589base 50 °F — the season’s usable heat
Longest day14 h 43 mindaylight on June 21
Shortest day9 h 36 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation7.8 inper year, rain and melted snow
Snowfall30 inper year

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 35 °F, low 5 °F 35°5° JanFebruary: average high 41 °F, low 13 °F 41°13° FebMarch: average high 53 °F, low 21 °F 53°21° MarApril: average high 60 °F, low 28 °F 60°28° AprMay: average high 69 °F, low 37 °F 69°37° MayJune: average high 79 °F, low 44 °F 79°44° JunJuly: average high 81 °F, low 49 °F 81°49° JulAugust: average high 79 °F, low 47 °F 79°47° AugSeptember: average high 73 °F, low 40 °F 73°40° SepOctober: average high 63 °F, low 28 °F 63°28° OctNovember: average high 49 °F, low 17 °F 49°17° NovDecember: average high 36 °F, low 6 °F 36°6° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 0.21 in precipitation, 4.6 in snowfall 0.2❄5 JanFebruary: 0.22 in precipitation, 3 in snowfall 0.2❄3 FebMarch: 0.43 in precipitation, 5.5 in snowfall 0.4❄6 MarApril: 0.53 in precipitation, 3.6 in snowfall 0.5❄4 AprMay: 0.59 in precipitation, 0.4 in snowfall 0.6 MayJune: 0.40 in precipitation 0.4 JunJuly: 1.08 in precipitation 1.1 JulAugust: 1.58 in precipitation 1.6 AugSeptember: 1.12 in precipitation 1.1 SepOctober: 0.67 in precipitation, 2.5 in snowfall 0.7❄3 OctNovember: 0.49 in precipitation, 4.5 in snowfall 0.5❄5 NovDecember: 0.43 in precipitation, 5.6 in snowfall 0.4❄6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Manassa, CO (2 mi away); precipitation: Manassa, CO (2 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.

811485a
Romeo, CO · 5 mi
811295a
Conejos, CO · 8 mi
811515a
Sanford, CO · 11 mi
811245a
Capulin, CO · 15 mi
811385a
Jaroso, CO · 18 mi
811405b
La Jara, CO · 18 mi
811014b
Alamosa, CO · 21 mi
875245a
Costilla, NM · 24 mi

Colorado planting zones →

Questions about 81141

What planting zone is ZIP code 81141?

ZIP code 81141 (Manassa, CO) 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 Manassa, CO?

The median last spring frost (32 °F) near 81141 is May 28; after June 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Manassa station.

When is the first frost in Manassa, CO?

The median first fall frost near 81141 is September 21, giving a median frost-free growing season of 115 days.

When should I plant tomatoes in 81141?

Start tomato seeds indoors around Apr 2 – Apr 16 and set transplants outside around Jun 4 – Jun 18, one to three weeks after the median last frost.

How much rain and snow does 81141 get?

About 7.8 inches of precipitation a year and 30 inches of snowfall (NOAA 1991–2020 normals, Manassa station).

How hot do summers get in Manassa, CO?

The average high peaks at 81 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 81141 have?

The USDA soil survey maps Quamon at the center of ZIP 81141: gravelly sandy loam, moderately well drained, pH about 8.2 (alkaline).

Did spring come early in Manassa, CO in 2026?

Spring leaf-out near 81141 came on Mar 23 in 2026, 23 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Manassa, CO?

Intermediate onions: the longest day near 81141 is 14 h 43 min, so day-neutral types bulb best; long-day varieties may not bulb fully.