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

Planting zone for 81071 — Sheridan Lake, CO

ZIP code 81071 (Sheridan Lake, Kiowa County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 27 and the first fall frost October 15.

Where ZIP 81071 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 27
First frostOct 15
2012 zone5b

Was 5b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sheridan Lake, 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 Sheridan Lake, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 27median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 15median — 10% chance by Oct 2
Growing season170 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 17 and returns around October 23.

From the NOAA station Sheridan Lake, CO — 3 miles away, elevation 4,072 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 81071

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 16 – Mar 30
SpinachSow outdoors · Mar 16 – Apr 6
Broccoli, cabbageStart indoors · Feb 16 – Mar 2
Broccoli, cabbageTransplant · Apr 6 – Apr 20
Onion setsPlant outdoors · Mar 30 – Apr 13
PotatoesPlant outdoors · Apr 6 – Apr 20
LettuceSow outdoors · Mar 30 – Apr 13
Carrots, beetsSow outdoors · Apr 6 – Apr 20
TomatoesStart indoors · Mar 2 – Mar 16
TomatoesTransplant · May 4 – May 18
Peppers, eggplantStart indoors · Feb 16 – Mar 2
Peppers, eggplantTransplant · May 11 – May 25
BeansSow outdoors · May 4 – May 18
Sweet cornSow outdoors · May 4 – May 18
Cucumbers, squashSow outdoors · May 4 – May 18
Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3
GarlicPlant cloves · Oct 1 – Nov 5
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 27) and first fall frost (Oct 15) 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 81071 came on Feb 27 — 20 days earlier than the 1991–2020 average (Mar 19).

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 6a in Colorado

563 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 28

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 104

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 251

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 167

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 4

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °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 Sheridan Lake, CO.

Soil in Sheridan Lake, CO

The soil mapped at the center of ZIP 81071 is Richfield — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.7%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Richfield silt loam, 0 to 1 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 81071; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sheridan Lake, CO

Summer high92 °Faverage high, July
Winter low14 °Faverage low, January
Hot days71days a year at 90 °F or more
Freezing nights154nights a year at 32 °F or less
Growing degree days3,480base 50 °F — the season’s usable heat
Longest day14 h 51 mindaylight on June 21
Shortest day9 h 29 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation16.3 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 44 °F, low 14 °F 44°14° JanFebruary: average high 47 °F, low 18 °F 47°18° FebMarch: average high 57 °F, low 26 °F 57°26° MarApril: average high 65 °F, low 35 °F 65°35° AprMay: average high 76 °F, low 46 °F 76°46° MayJune: average high 87 °F, low 57 °F 87°57° JunJuly: average high 92 °F, low 62 °F 92°62° JulAugust: average high 89 °F, low 61 °F 89°61° AugSeptember: average high 82 °F, low 52 °F 82°52° SepOctober: average high 69 °F, low 37 °F 69°37° OctNovember: average high 55 °F, low 26 °F 55°26° NovDecember: average high 45 °F, low 16 °F 45°16° Dec

Precipitation by month inches

0″1″2″3″January: 0.30 in precipitation 0.3 JanFebruary: 0.42 in precipitation 0.4 FebMarch: 0.66 in precipitation 0.7 MarApril: 1.46 in precipitation 1.5 AprMay: 2.17 in precipitation 2.2 MayJune: 2.41 in precipitation 2.4 JunJuly: 3.00 in precipitation 3.0 JulAugust: 2.62 in precipitation 2.6 AugSeptember: 1.02 in precipitation 1.0 SepOctober: 1.36 in precipitation 1.4 OctNovember: 0.41 in precipitation 0.4 NovDecember: 0.44 in precipitation 0.4 Dec

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

810436a
Hartman, CO · 22 mi
678796a
Tribune, KS · 25 mi
808026a
Arapahoe, CO · 28 mi
808106a
Cheyenne Wells, CO · 28 mi
810366a
Eads, CO · 29 mi
810476a
Holly, CO · 30 mi
678366a
Coolidge, KS · 31 mi
677626a
Weskan, KS · 32 mi

Colorado planting zones →

Questions about 81071

What planting zone is ZIP code 81071?

ZIP code 81071 (Sheridan Lake, CO) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Sheridan Lake, CO?

The median last spring frost (32 °F) near 81071 is April 27; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sheridan Lake station.

When is the first frost in Sheridan Lake, CO?

The median first fall frost near 81071 is October 15, giving a median frost-free growing season of 170 days.

When should I plant tomatoes in 81071?

Start tomato seeds indoors around Mar 2 – Mar 16 and set transplants outside around May 4 – May 18, one to three weeks after the median last frost.

How much rain and snow does 81071 get?

About 16.3 inches of precipitation a year (NOAA 1991–2020 normals, Sheridan Lake station).

How hot do summers get in Sheridan Lake, CO?

The average high peaks at 92 °F in July, with about 71 days a year at 90 °F or more.

What kind of soil does 81071 have?

The USDA soil survey maps Richfield at the center of ZIP 81071: silt loam, well drained, pH about 7.2 (neutral).

Did spring come early in Sheridan Lake, CO in 2026?

Spring leaf-out near 81071 came on Feb 27 in 2026, 20 days earlier than the 1991–2020 average (Mar 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sheridan Lake, CO?

Intermediate onions: the longest day near 81071 is 14 h 51 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 81071 change?

Yes. The 2012 USDA map put 81071 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.