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

Planting zone for 81423 — Norwood, CO

ZIP code 81423 (Norwood, San Miguel County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 25 and the first fall frost October 1.

Where ZIP 81423 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 25
First frostOct 1
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Norwood, 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 Norwood, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 25median — 50% chance of a later frost
Safe for tender plantsJune 13only 10% chance of frost after
First fall frostOctober 1median — 10% chance by Sep 14
Growing season128 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 11 and returns around October 8.

From the NOAA station Norwood, CO — 11 miles away, elevation 7,021 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 81423

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 13 – Apr 27
SpinachSow outdoors · Apr 13 – May 4
Broccoli, cabbageStart indoors · Mar 16 – Mar 30
Broccoli, cabbageTransplant · May 4 – May 18
Onion setsPlant outdoors · Apr 27 – May 11
PotatoesPlant outdoors · May 4 – May 18
LettuceSow outdoors · Apr 27 – May 11
Carrots, beetsSow outdoors · May 4 – May 18
TomatoesStart indoors · Mar 30 – Apr 13
TomatoesTransplant · Jun 1 – Jun 15
Peppers, eggplantStart indoors · Mar 16 – Mar 30
Peppers, eggplantTransplant · Jun 8 – Jun 22
BeansSow outdoors · Jun 1 – Jun 15
Sweet cornSow outdoors · Jun 1 – Jun 15
Cucumbers, squashSow outdoors · Jun 1 – Jun 15
Fall lettuce, spinachSow outdoors · Aug 6 – Aug 20
GarlicPlant cloves · Sep 17 – Oct 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 25) and first fall frost (Oct 1) 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 81423 came on Mar 31 — 23 days earlier than the 1991–2020 average (Apr 23).

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 Norwood, CO.

Soil in Norwood, CO

The soil mapped at the center of ZIP 81423 is Narraguinnep — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Narraguinnep clay loam, moist, 15 to 50 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 81423; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Norwood, CO

Summer high85 °Faverage high, July
Winter low13 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights183nights a year at 32 °F or less
Growing degree days2,044base 50 °F — the season’s usable heat
Longest day14 h 48 mindaylight on June 21
Shortest day9 h 31 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation15.8 inper year, rain and melted snow
Snowfall60 inper year

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 39 °F, low 13 °F 39°13° JanFebruary: average high 43 °F, low 18 °F 43°18° FebMarch: average high 52 °F, low 25 °F 52°25° MarApril: average high 59 °F, low 31 °F 59°31° AprMay: average high 69 °F, low 38 °F 69°38° MayJune: average high 81 °F, low 46 °F 81°46° JunJuly: average high 85 °F, low 53 °F 85°53° JulAugust: average high 82 °F, low 51 °F 82°51° AugSeptember: average high 75 °F, low 44 °F 75°44° SepOctober: average high 62 °F, low 34 °F 62°34° OctNovember: average high 50 °F, low 23 °F 50°23° NovDecember: average high 39 °F, low 14 °F 39°14° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.90 in precipitation, 12 in snowfall 0.9❄12 JanFebruary: 0.74 in precipitation, 10.4 in snowfall 0.7❄10 FebMarch: 0.97 in precipitation, 8 in snowfall 1.0❄8 MarApril: 1.13 in precipitation, 4.2 in snowfall 1.1❄4 AprMay: 1.18 in precipitation, 0.6 in snowfall 1.2❄1 MayJune: 0.66 in precipitation 0.7 JunJuly: 2.00 in precipitation 2.0 JulAugust: 2.17 in precipitation 2.2 AugSeptember: 2.04 in precipitation, 0.2 in snowfall 2.0 SepOctober: 1.48 in precipitation, 2.1 in snowfall 1.5❄2 OctNovember: 1.31 in precipitation, 11.9 in snowfall 1.3❄12 NovDecember: 1.17 in precipitation, 10.4 in snowfall 1.2❄10 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Norwood, CO (11 mi away); precipitation: Norwood, CO (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

814316b
Redvale, CO · 10 mi
813256b
Egnar, CO · 17 mi
814305b
Placerville, CO · 20 mi
814246a
Nucla, CO · 24 mi
813206b
Cahone, CO · 26 mi
814226b
Naturita, CO · 26 mi
813236a
Dolores, CO · 27 mi
814355b
Telluride, CO · 29 mi

Colorado planting zones →

Questions about 81423

What planting zone is ZIP code 81423?

ZIP code 81423 (Norwood, 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 Norwood, CO?

The median last spring frost (32 °F) near 81423 is May 25; after June 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Norwood station.

When is the first frost in Norwood, CO?

The median first fall frost near 81423 is October 1, giving a median frost-free growing season of 128 days.

When should I plant tomatoes in 81423?

Start tomato seeds indoors around Mar 30 – Apr 13 and set transplants outside around Jun 1 – Jun 15, one to three weeks after the median last frost.

How much rain and snow does 81423 get?

About 15.8 inches of precipitation a year and 60 inches of snowfall (NOAA 1991–2020 normals, Norwood station).

How hot do summers get in Norwood, CO?

The average high peaks at 85 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 81423 have?

The USDA soil survey maps Narraguinnep at the center of ZIP 81423: clay loam, well drained, pH about 7.0 (neutral).

Did spring come early in Norwood, CO in 2026?

Spring leaf-out near 81423 came on Mar 31 in 2026, 23 days earlier than the 1991–2020 average (Apr 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Norwood, CO?

Intermediate onions: the longest day near 81423 is 14 h 48 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 81423 change?

Yes. The 2012 USDA map put 81423 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.