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

Planting zone for 80644 — Kersey, CO

ZIP code 80644 (Kersey, Weld County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 2 and the first fall frost October 8.

Where ZIP 80644 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 2
First frostOct 8
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 Kersey, 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 Kersey, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 2median — 50% chance of a later frost
Safe for tender plantsMay 14only 10% chance of frost after
First fall frostOctober 8median — 10% chance by Sep 26
Growing season159 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 20 and returns around October 18.

From the NOAA station Greeley Unc, CO — 15 miles away, elevation 4,715 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 80644

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 21 – Apr 4
SpinachSow outdoors · Mar 21 – Apr 11
Broccoli, cabbageStart indoors · Feb 21 – Mar 7
Broccoli, cabbageTransplant · Apr 11 – Apr 25
Onion setsPlant outdoors · Apr 4 – Apr 18
PotatoesPlant outdoors · Apr 11 – Apr 25
LettuceSow outdoors · Apr 4 – Apr 18
Carrots, beetsSow outdoors · Apr 11 – Apr 25
TomatoesStart indoors · Mar 7 – Mar 21
TomatoesTransplant · May 9 – May 23
Peppers, eggplantStart indoors · Feb 21 – Mar 7
Peppers, eggplantTransplant · May 16 – May 30
BeansSow outdoors · May 9 – May 23
Sweet cornSow outdoors · May 9 – May 23
Cucumbers, squashSow outdoors · May 9 – May 23
Fall lettuce, spinachSow outdoors · Aug 13 – Aug 27
GarlicPlant cloves · Sep 24 – Oct 29
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 2) and first fall frost (Oct 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 80644 came on Mar 1 — 27 days earlier than the 1991–2020 average (Mar 28).

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 Kersey, CO.

Soil in Kersey, CO

The soil mapped at the center of ZIP 80644 is Valent — sand, excessively drained.

TextureSanddrains and warms fast; dries out and needs more feeding
pH6.6neutral; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter0.9%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Valent sand, 3 to 9 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 80644; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kersey, CO

Summer high92 °Faverage high, July
Winter low18 °Faverage low, January
Hot days58days a year at 90 °F or more
Freezing nights153nights a year at 32 °F or less
Growing degree days3,210base 50 °F — the season’s usable heat
Longest day15 h 03 mindaylight on June 21
Shortest day9 h 17 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation14.2 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 44 °F, low 18 °F 44°18° JanFebruary: average high 48 °F, low 20 °F 48°20° FebMarch: average high 59 °F, low 28 °F 59°28° MarApril: average high 66 °F, low 35 °F 66°35° AprMay: average high 75 °F, low 45 °F 75°45° MayJune: average high 86 °F, low 54 °F 86°54° JunJuly: average high 92 °F, low 59 °F 92°59° JulAugust: average high 89 °F, low 57 °F 89°57° AugSeptember: average high 82 °F, low 49 °F 82°49° SepOctober: average high 68 °F, low 37 °F 68°37° OctNovember: average high 54 °F, low 26 °F 54°26° NovDecember: average high 43 °F, low 18 °F 43°18° Dec

Precipitation by month inches

0″1″2″3″January: 0.33 in precipitation 0.3 JanFebruary: 0.30 in precipitation 0.3 FebMarch: 1.01 in precipitation 1.0 MarApril: 1.64 in precipitation 1.6 AprMay: 2.75 in precipitation 2.8 MayJune: 1.69 in precipitation 1.7 JunJuly: 1.63 in precipitation 1.6 JulAugust: 1.58 in precipitation 1.6 AugSeptember: 1.17 in precipitation 1.2 SepOctober: 1.14 in precipitation 1.1 OctNovember: 0.57 in precipitation 0.6 NovDecember: 0.40 in precipitation 0.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Greeley Unc, CO (15 mi away); precipitation: Kersey 4.5 E, CO (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

806245a
Gill, CO · 7 mi
806455a
La Salle, CO · 12 mi
806495a
Orchard, CO · 14 mi
806225a
Galeton, CO · 14 mi
806315a
Greeley, CO · 15 mi
806205b
Evans, CO · 15 mi
806435b
Keenesburg, CO · 16 mi
806525b
Roggen, CO · 16 mi

Colorado planting zones →

Questions about 80644

What planting zone is ZIP code 80644?

ZIP code 80644 (Kersey, 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 Kersey, CO?

The median last spring frost (32 °F) near 80644 is May 2; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Greeley Unc station.

When is the first frost in Kersey, CO?

The median first fall frost near 80644 is October 8, giving a median frost-free growing season of 159 days.

When should I plant tomatoes in 80644?

Start tomato seeds indoors around Mar 7 – Mar 21 and set transplants outside around May 9 – May 23, one to three weeks after the median last frost.

How much rain and snow does 80644 get?

About 14.2 inches of precipitation a year (NOAA 1991–2020 normals, Kersey 4.5 E station).

How hot do summers get in Kersey, CO?

The average high peaks at 92 °F in July, with about 58 days a year at 90 °F or more.

What kind of soil does 80644 have?

The USDA soil survey maps Valent at the center of ZIP 80644: sand, excessively drained, pH about 6.6 (neutral).

Did spring come early in Kersey, CO in 2026?

Spring leaf-out near 80644 came on Mar 1 in 2026, 27 days earlier than the 1991–2020 average (Mar 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Kersey, CO?

Long-day onions: the longest day near 80644 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).