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

Planting zone for 80734 — Holyoke, CO

ZIP code 80734 (Holyoke, Phillips County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 11 and the first fall frost October 3.

Where ZIP 80734 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 11
First frostOct 3
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 Holyoke, 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 Holyoke, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 11median — 50% chance of a later frost
Safe for tender plantsMay 23only 10% chance of frost after
First fall frostOctober 3median — 10% chance by Sep 20
Growing season144 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 12.

From the NOAA station Holyoke, CO — 3 miles away, elevation 3,780 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 80734

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 30 – Apr 13
SpinachSow outdoors · Mar 30 – Apr 20
Broccoli, cabbageStart indoors · Mar 2 – Mar 16
Broccoli, cabbageTransplant · Apr 20 – May 4
Onion setsPlant outdoors · Apr 13 – Apr 27
PotatoesPlant outdoors · Apr 20 – May 4
LettuceSow outdoors · Apr 13 – Apr 27
Carrots, beetsSow outdoors · Apr 20 – May 4
TomatoesStart indoors · Mar 16 – Mar 30
TomatoesTransplant · May 18 – Jun 1
Peppers, eggplantStart indoors · Mar 2 – Mar 16
Peppers, eggplantTransplant · May 25 – Jun 8
BeansSow outdoors · May 18 – Jun 1
Sweet cornSow outdoors · May 18 – Jun 1
Cucumbers, squashSow outdoors · May 18 – Jun 1
Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22
GarlicPlant cloves · Sep 19 – Oct 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 11) and first fall frost (Oct 3) 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 80734 came on Feb 26 — 27 days earlier than the 1991–2020 average (Mar 25).

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 Holyoke, CO.

Soil in Holyoke, CO

The soil mapped at the center of ZIP 80734 is Platner — loam, well drained.

TextureLoama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.1%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Platner loam, 3 to 5 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 80734; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Holyoke, CO

Summer high88 °Faverage high, July
Winter low13 °Faverage low, January
Hot days40days a year at 90 °F or more
Freezing nights170nights a year at 32 °F or less
Growing degree days2,755base 50 °F — the season’s usable heat
Longest day15 h 04 mindaylight on June 21
Shortest day9 h 16 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation17.9 inper year, rain and melted snow
Snowfall30 inper year; 31 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 42 °F, low 13 °F 42°13° JanFebruary: average high 44 °F, low 15 °F 44°15° FebMarch: average high 54 °F, low 23 °F 54°23° MarApril: average high 62 °F, low 31 °F 62°31° AprMay: average high 71 °F, low 43 °F 71°43° MayJune: average high 83 °F, low 53 °F 83°53° JunJuly: average high 88 °F, low 59 °F 88°59° JulAugust: average high 86 °F, low 56 °F 86°56° AugSeptember: average high 79 °F, low 47 °F 79°47° SepOctober: average high 65 °F, low 33 °F 65°33° OctNovember: average high 53 °F, low 21 °F 53°21° NovDecember: average high 42 °F, low 13 °F 42°13° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.32 in precipitation, 4.5 in snowfall 0.3❄5 JanFebruary: 0.51 in precipitation, 6.1 in snowfall 0.5❄6 FebMarch: 0.86 in precipitation, 4.4 in snowfall 0.9❄4 MarApril: 1.92 in precipitation, 3.7 in snowfall 1.9❄4 AprMay: 2.83 in precipitation, 0.2 in snowfall 2.8 MayJune: 2.76 in precipitation 2.8 JunJuly: 2.75 in precipitation 2.8 JulAugust: 2.39 in precipitation 2.4 AugSeptember: 1.40 in precipitation, 0.2 in snowfall 1.4 SepOctober: 1.23 in precipitation, 1.9 in snowfall 1.2❄2 OctNovember: 0.52 in precipitation, 3.9 in snowfall 0.5❄4 NovDecember: 0.44 in precipitation, 5.5 in snowfall 0.4❄6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Holyoke, CO (3 mi away); precipitation: Holyoke, CO (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

807465b
Paoli, CO · 11 mi
807215b
Amherst, CO · 14 mi
807315b
Haxtun, CO · 17 mi
690235b
Champion, NE · 21 mi
691685b
Venango, NE · 23 mi
807445b
Ovid, CO · 25 mi
807375b
Julesburg, CO · 26 mi
807585b
Wray, CO · 27 mi

Colorado planting zones →

Questions about 80734

What planting zone is ZIP code 80734?

ZIP code 80734 (Holyoke, 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 Holyoke, CO?

The median last spring frost (32 °F) near 80734 is May 11; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Holyoke station.

When is the first frost in Holyoke, CO?

The median first fall frost near 80734 is October 3, giving a median frost-free growing season of 144 days.

When should I plant tomatoes in 80734?

Start tomato seeds indoors around Mar 16 – Mar 30 and set transplants outside around May 18 – Jun 1, one to three weeks after the median last frost.

How much rain and snow does 80734 get?

About 17.9 inches of precipitation a year and 30 inches of snowfall (NOAA 1991–2020 normals, Holyoke station).

How hot do summers get in Holyoke, CO?

The average high peaks at 88 °F in July, with about 40 days a year at 90 °F or more.

What kind of soil does 80734 have?

The USDA soil survey maps Platner at the center of ZIP 80734: loam, well drained, pH about 7.2 (neutral).

Did spring come early in Holyoke, CO in 2026?

Spring leaf-out near 80734 came on Feb 26 in 2026, 27 days earlier than the 1991–2020 average (Mar 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Holyoke, CO?

Long-day onions: the longest day near 80734 is 15 h 04 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).