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

Planting zone for 80823 — Karval, CO

ZIP code 80823 (Karval, Lincoln County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 9 and the first fall frost October 6.

Where ZIP 80823 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 9
First frostOct 6
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 Karval, 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 Karval, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 9median — 50% chance of a later frost
Safe for tender plantsMay 23only 10% chance of frost after
First fall frostOctober 6median — 10% chance by Sep 25
Growing season149 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 14.

From the NOAA station Karval, CO — 9 miles away, elevation 5,076 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 80823

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 28 – Apr 11
SpinachSow outdoors · Mar 28 – Apr 18
Broccoli, cabbageStart indoors · Feb 28 – Mar 14
Broccoli, cabbageTransplant · Apr 18 – May 2
Onion setsPlant outdoors · Apr 11 – Apr 25
PotatoesPlant outdoors · Apr 18 – May 2
LettuceSow outdoors · Apr 11 – Apr 25
Carrots, beetsSow outdoors · Apr 18 – May 2
TomatoesStart indoors · Mar 14 – Mar 28
TomatoesTransplant · May 16 – May 30
Peppers, eggplantStart indoors · Feb 28 – Mar 14
Peppers, eggplantTransplant · May 23 – Jun 6
BeansSow outdoors · May 16 – May 30
Sweet cornSow outdoors · May 16 – May 30
Cucumbers, squashSow outdoors · May 16 – May 30
Fall lettuce, spinachSow outdoors · Aug 11 – Aug 25
GarlicPlant cloves · Sep 22 – Oct 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 6) 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 80823 came on Mar 2 — 19 days earlier than the 1991–2020 average (Mar 21).

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 Karval, CO.

Soil in Karval, CO

The soil mapped at the center of ZIP 80823 is Manzanola — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH7.6slightly alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Manzanola clay loam, 1 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 80823; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Karval, CO

Summer high89 °Faverage high, July
Winter low15 °Faverage low, January
Hot days43days a year at 90 °F or more
Freezing nights169nights a year at 32 °F or less
Growing degree days2,823base 50 °F — the season’s usable heat
Longest day14 h 52 mindaylight on June 21
Shortest day9 h 27 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation14.4 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 46 °F, low 15 °F 46°15° JanFebruary: average high 48 °F, low 17 °F 48°17° FebMarch: average high 56 °F, low 25 °F 56°25° MarApril: average high 64 °F, low 32 °F 64°32° AprMay: average high 73 °F, low 42 °F 73°42° MayJune: average high 84 °F, low 52 °F 84°52° JunJuly: average high 89 °F, low 58 °F 89°58° JulAugust: average high 86 °F, low 56 °F 86°56° AugSeptember: average high 80 °F, low 47 °F 80°47° SepOctober: average high 67 °F, low 34 °F 67°34° OctNovember: average high 54 °F, low 23 °F 54°23° NovDecember: average high 45 °F, low 16 °F 45°16° Dec

Precipitation by month inches

0″1″2″3″January: 0.25 in precipitation 0.3 JanFebruary: 0.30 in precipitation 0.3 FebMarch: 0.74 in precipitation 0.7 MarApril: 1.30 in precipitation 1.3 AprMay: 2.14 in precipitation 2.1 MayJune: 1.89 in precipitation 1.9 JunJuly: 2.90 in precipitation 2.9 JulAugust: 2.50 in precipitation 2.5 AugSeptember: 1.03 in precipitation 1.0 SepOctober: 0.83 in precipitation 0.8 OctNovember: 0.31 in precipitation 0.3 NovDecember: 0.24 in precipitation 0.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Karval, CO (9 mi away); precipitation: Karval 0.2 Ne, CO (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

810455b
Haswell, CO · 16 mi
810215b
Arlington, CO · 17 mi
808215b
Hugo, CO · 23 mi
810765b
Sugar City, CO · 24 mi
808325b
Ramah, CO · 25 mi
810635b
Ordway, CO · 25 mi
808626a
Wild Horse, CO · 26 mi
808335b
Rush, CO · 30 mi

Colorado planting zones →

Questions about 80823

What planting zone is ZIP code 80823?

ZIP code 80823 (Karval, 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 Karval, CO?

The median last spring frost (32 °F) near 80823 is May 9; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Karval station.

When is the first frost in Karval, CO?

The median first fall frost near 80823 is October 6, giving a median frost-free growing season of 149 days.

When should I plant tomatoes in 80823?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 80823 get?

About 14.4 inches of precipitation a year (NOAA 1991–2020 normals, Karval 0.2 Ne station).

How hot do summers get in Karval, 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 80823 have?

The USDA soil survey maps Manzanola at the center of ZIP 80823: clay loam, well drained, pH about 7.6 (slightly alkaline).

Did spring come early in Karval, CO in 2026?

Spring leaf-out near 80823 came on Mar 2 in 2026, 19 days earlier than the 1991–2020 average (Mar 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Karval, CO?

Intermediate onions: the longest day near 80823 is 14 h 52 min, so day-neutral types bulb best; long-day varieties may not bulb fully.