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

Planting zone for 80421 — Bailey, CO

ZIP code 80421 (Bailey, Park County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is June 16 and the first fall frost September 8.

Where ZIP 80421 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 16
First frostSep 8
2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Bailey, 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 Bailey, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 16median — 50% chance of a later frost
Safe for tender plantsJuly 1only 10% chance of frost after
First fall frostSeptember 8median — 10% chance by Aug 27
Growing season84 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 30 and returns around September 19.

From the NOAA station Bailey, CO — 4 miles away, elevation 7,753 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 80421

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · May 5 – May 19
SpinachSow outdoors · May 5 – May 26
Broccoli, cabbageStart indoors · Apr 7 – Apr 21
Broccoli, cabbageTransplant · May 26 – Jun 9
Onion setsPlant outdoors · May 19 – Jun 2
PotatoesPlant outdoors · May 26 – Jun 9
LettuceSow outdoors · May 19 – Jun 2
Carrots, beetsSow outdoors · May 26 – Jun 9
TomatoesStart indoors · Apr 21 – May 5
TomatoesTransplant · Jun 23 – Jul 7
Peppers, eggplantStart indoors · Apr 7 – Apr 21
Peppers, eggplantTransplant · Jun 30 – Jul 14
BeansSow outdoors · Jun 23 – Jul 7
Sweet cornSow outdoors · Jun 23 – Jul 7
Cucumbers, squashSow outdoors · Jun 23 – Jul 7
Fall lettuce, spinachSow outdoors · Jul 14 – Jul 28
GarlicPlant cloves · Aug 25 – Sep 29
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 16) and first fall frost (Sep 8) 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 80421 came on Apr 1 — 37 days earlier than the 1991–2020 average (May 8).

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.

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 98

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 246

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 163

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 Bailey, CO.

Soil in Bailey, CO

The soil mapped at the center of ZIP 80421 is Legault family — slightly decomposed plant material, excessively drained.

TextureSlightly decomposed plant materialtop layer
pH5.0strongly acidic; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter75%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Legault family-Rock outcrop complex, 40 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 80421; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bailey, CO

Summer high79 °Faverage high, July
Winter low9 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights235nights a year at 32 °F or less
Growing degree days1,085base 50 °F — the season’s usable heat
Longest day14 h 57 mindaylight on June 21
Shortest day9 h 23 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation20.6 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 38 °F, low 9 °F 38°9° JanFebruary: average high 40 °F, low 10 °F 40°10° FebMarch: average high 48 °F, low 18 °F 48°18° MarApril: average high 54 °F, low 23 °F 54°23° AprMay: average high 63 °F, low 31 °F 63°31° MayJune: average high 75 °F, low 38 °F 75°38° JunJuly: average high 79 °F, low 44 °F 79°44° JulAugust: average high 77 °F, low 43 °F 77°43° AugSeptember: average high 71 °F, low 35 °F 71°35° SepOctober: average high 59 °F, low 25 °F 59°25° OctNovember: average high 45 °F, low 16 °F 45°16° NovDecember: average high 37 °F, low 9 °F 37°9° Dec

Precipitation by month inches

0″1″2″3″4″January: 0.67 in precipitation 0.7 JanFebruary: 0.83 in precipitation 0.8 FebMarch: 1.51 in precipitation 1.5 MarApril: 2.20 in precipitation 2.2 AprMay: 2.36 in precipitation 2.4 MayJune: 1.77 in precipitation 1.8 JunJuly: 3.71 in precipitation 3.7 JulAugust: 3.10 in precipitation 3.1 AugSeptember: 1.71 in precipitation 1.7 SepOctober: 1.17 in precipitation 1.2 OctNovember: 0.83 in precipitation 0.8 NovDecember: 0.70 in precipitation 0.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bailey, CO (4 mi away); precipitation: Bailey 6.4 Nnw, 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.

804755b
Shawnee, CO · 7 mi
804335b
Conifer, CO · 11 mi
804705b
Pine, CO · 11 mi
804395b
Evergreen, CO · 12 mi
804565a
Jefferson, CO · 14 mi
804575b
Kittredge, CO · 17 mi
804445a
Georgetown, CO · 17 mi
804485b
Grant, CO · 18 mi

Colorado planting zones →

Questions about 80421

What planting zone is ZIP code 80421?

ZIP code 80421 (Bailey, 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 Bailey, CO?

The median last spring frost (32 °F) near 80421 is June 16; after July 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bailey station.

When is the first frost in Bailey, CO?

The median first fall frost near 80421 is September 8, giving a median frost-free growing season of 84 days.

When should I plant tomatoes in 80421?

Start tomato seeds indoors around Apr 21 – May 5 and set transplants outside around Jun 23 – Jul 7, one to three weeks after the median last frost.

How much rain and snow does 80421 get?

About 20.6 inches of precipitation a year (NOAA 1991–2020 normals, Bailey 6.4 Nnw station).

How hot do summers get in Bailey, CO?

The average high peaks at 79 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 80421 have?

The USDA soil survey maps Legault family at the center of ZIP 80421: slightly decomposed plant material, excessively drained, pH about 5.0 (strongly acidic).

Did spring come early in Bailey, CO in 2026?

Spring leaf-out near 80421 came on Apr 1 in 2026, 37 days earlier than the 1991–2020 average (May 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bailey, CO?

Intermediate onions: the longest day near 80421 is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.