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

Planting zone for 80801 — Anton, CO

ZIP code 80801 (Anton, Washington County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 12 and the first fall frost October 4.

Where ZIP 80801 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 frostMay 12
First frostOct 4
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 Anton, 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 Anton, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 12median — 50% chance of a later frost
Safe for tender plantsMay 26only 10% chance of frost after
First fall frostOctober 4median — 10% chance by Sep 21
Growing season143 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 13.

From the NOAA station Shaw 4ene, CO — 15 miles away, elevation 5,000 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 80801

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 31 – Apr 14
SpinachSow outdoors · Mar 31 – Apr 21
Broccoli, cabbageStart indoors · Mar 3 – Mar 17
Broccoli, cabbageTransplant · Apr 21 – May 5
Onion setsPlant outdoors · Apr 14 – Apr 28
PotatoesPlant outdoors · Apr 21 – May 5
LettuceSow outdoors · Apr 14 – Apr 28
Carrots, beetsSow outdoors · Apr 21 – May 5
TomatoesStart indoors · Mar 17 – Mar 31
TomatoesTransplant · May 19 – Jun 2
Peppers, eggplantStart indoors · Mar 3 – Mar 17
Peppers, eggplantTransplant · May 26 – Jun 9
BeansSow outdoors · May 19 – Jun 2
Sweet cornSow outdoors · May 19 – Jun 2
Cucumbers, squashSow outdoors · May 19 – Jun 2
Fall lettuce, spinachSow outdoors · Aug 9 – Aug 23
GarlicPlant cloves · Sep 20 – Oct 25
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 12) and first fall frost (Oct 4) 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 80801 came on Mar 1 — 26 days earlier than the 1991–2020 average (Mar 27).

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 Anton, CO.

Soil in Anton, CO

The soil mapped at the center of ZIP 80801 is Weld — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Weld silt loam, 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 80801; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Anton, CO

Summer high89 °Faverage high, July
Winter low14 °Faverage low, January
Hot days43days a year at 90 °F or more
Freezing nights175nights a year at 32 °F or less
Growing degree days2,703base 50 °F — the season’s usable heat
Longest day14 h 59 mindaylight on June 21
Shortest day9 h 21 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation17.5 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 42 °F, low 14 °F 42°14° JanFebruary: average high 44 °F, low 15 °F 44°15° FebMarch: average high 55 °F, low 24 °F 55°24° MarApril: average high 61 °F, low 31 °F 61°31° AprMay: average high 71 °F, low 41 °F 71°41° MayJune: average high 83 °F, low 51 °F 83°51° JunJuly: average high 89 °F, low 57 °F 89°57° JulAugust: average high 86 °F, low 56 °F 86°56° AugSeptember: average high 79 °F, low 46 °F 79°46° SepOctober: average high 65 °F, low 33 °F 65°33° OctNovember: average high 52 °F, low 23 °F 52°23° NovDecember: average high 42 °F, low 15 °F 42°15° Dec

Precipitation by month inches

0″1″2″3″January: 0.35 in precipitation 0.3 JanFebruary: 0.56 in precipitation 0.6 FebMarch: 0.89 in precipitation 0.9 MarApril: 1.60 in precipitation 1.6 AprMay: 2.65 in precipitation 2.6 MayJune: 2.43 in precipitation 2.4 JunJuly: 2.98 in precipitation 3.0 JulAugust: 2.43 in precipitation 2.4 AugSeptember: 1.40 in precipitation 1.4 SepOctober: 1.25 in precipitation 1.3 OctNovember: 0.56 in precipitation 0.6 NovDecember: 0.44 in precipitation 0.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Shaw 4ene, CO (15 mi away); precipitation: Anton 5.8 Se, CO (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

807405b
Lindon, CO · 15 mi
808125b
Cope, CO · 16 mi
808225b
Joes, CO · 23 mi
808155b
Flagler, CO · 24 mi
807205b
Akron, CO · 24 mi
807575b
Woodrow, CO · 26 mi
808045b
Arriba, CO · 28 mi
808185b
Genoa, CO · 29 mi

Colorado planting zones →

Questions about 80801

What planting zone is ZIP code 80801?

ZIP code 80801 (Anton, 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 Anton, CO?

The median last spring frost (32 °F) near 80801 is May 12; after May 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Shaw 4ene station.

When is the first frost in Anton, CO?

The median first fall frost near 80801 is October 4, giving a median frost-free growing season of 143 days.

When should I plant tomatoes in 80801?

Start tomato seeds indoors around Mar 17 – Mar 31 and set transplants outside around May 19 – Jun 2, one to three weeks after the median last frost.

How much rain and snow does 80801 get?

About 17.5 inches of precipitation a year (NOAA 1991–2020 normals, Anton 5.8 Se station).

How hot do summers get in Anton, CO?

The average high peaks at 89 °F in July, with about 43 days a year at 90 °F or more.

What kind of soil does 80801 have?

The USDA soil survey maps Weld at the center of ZIP 80801: silt loam, well drained, pH about 7.0 (neutral).

Did spring come early in Anton, CO in 2026?

Spring leaf-out near 80801 came on Mar 1 in 2026, 26 days earlier than the 1991–2020 average (Mar 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Anton, CO?

Intermediate onions: the longest day near 80801 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.