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

Planting zone for 80261 — Denver, CO

ZIP code 80261 (Denver, Denver County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 30 and the first fall frost October 12.

Where ZIP 80261 is

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 30
First frostOct 12
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 Denver, 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 Denver, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 30median — 50% chance of a later frost
Safe for tender plantsMay 13only 10% chance of frost after
First fall frostOctober 12median — 10% chance by Sep 28
Growing season165 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around October 21.

From the NOAA station Denver Water Dept, CO — within 1 mile, elevation 5,230 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 80261

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 19 – Apr 2
SpinachSow outdoors · Mar 19 – Apr 9
Broccoli, cabbageStart indoors · Feb 19 – Mar 5
Broccoli, cabbageTransplant · Apr 9 – Apr 23
Onion setsPlant outdoors · Apr 2 – Apr 16
PotatoesPlant outdoors · Apr 9 – Apr 23
LettuceSow outdoors · Apr 2 – Apr 16
Carrots, beetsSow outdoors · Apr 9 – Apr 23
TomatoesStart indoors · Mar 5 – Mar 19
TomatoesTransplant · May 7 – May 21
Peppers, eggplantStart indoors · Feb 19 – Mar 5
Peppers, eggplantTransplant · May 14 – May 28
BeansSow outdoors · May 7 – May 21
Sweet cornSow outdoors · May 7 – May 21
Cucumbers, squashSow outdoors · May 7 – May 21
Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31
GarlicPlant cloves · Sep 28 – Nov 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 12) 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 80261 came on Feb 19 — 25 days earlier than the 1991–2020 average (Mar 16).

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 Denver, CO.

Soil in Denver, CO

The soil mapped at the center of ZIP 80261 is Vona — sandy loam, well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Vona-Elyria complex, 0 to 15 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 80261; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Denver, CO

Summer high91 °Faverage high, July
Winter low21 °Faverage low, January
Hot days64days a year at 90 °F or more
Freezing nights150nights a year at 32 °F or less
Growing degree days3,396base 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
Precipitation17.9 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 49 °F, low 21 °F 49°21° JanFebruary: average high 49 °F, low 22 °F 49°22° FebMarch: average high 58 °F, low 30 °F 58°30° MarApril: average high 64 °F, low 36 °F 64°36° AprMay: average high 73 °F, low 46 °F 73°46° MayJune: average high 85 °F, low 56 °F 85°56° JunJuly: average high 91 °F, low 62 °F 91°62° JulAugust: average high 90 °F, low 60 °F 90°60° AugSeptember: average high 82 °F, low 51 °F 82°51° SepOctober: average high 68 °F, low 38 °F 68°38° OctNovember: average high 56 °F, low 28 °F 56°28° NovDecember: average high 47 °F, low 21 °F 47°21° Dec

Precipitation by month inches

0″1″2″3″January: 0.56 in precipitation 0.6 JanFebruary: 0.70 in precipitation 0.7 FebMarch: 1.13 in precipitation 1.1 MarApril: 2.22 in precipitation 2.2 AprMay: 2.51 in precipitation 2.5 MayJune: 2.99 in precipitation 3.0 JunJuly: 2.25 in precipitation 2.3 JulAugust: 1.63 in precipitation 1.6 AugSeptember: 1.24 in precipitation 1.2 SepOctober: 1.31 in precipitation 1.3 OctNovember: 0.76 in precipitation 0.8 NovDecember: 0.59 in precipitation 0.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Denver Water Dept, CO (within 1 mile); precipitation: Denver 1 Sw 7news, CO (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

802086a
Denver, CO · <1 mi
802176a
Denver, CO · <1 mi
802436a
Denver, CO · <1 mi
802446a
Denver, CO · <1 mi
802486a
Denver, CO · <1 mi
802506a
Denver, CO · <1 mi
802576a
Denver, CO · <1 mi
802636a
Denver, CO · <1 mi

All 59 ZIP codes in Denver → · Colorado planting zones →

Questions about 80261

What planting zone is ZIP code 80261?

ZIP code 80261 (Denver, 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 Denver, CO?

The median last spring frost (32 °F) near 80261 is April 30; after May 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Denver Water Dept station.

When is the first frost in Denver, CO?

The median first fall frost near 80261 is October 12, giving a median frost-free growing season of 165 days.

When should I plant tomatoes in 80261?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 80261 get?

About 17.9 inches of precipitation a year (NOAA 1991–2020 normals, Denver 1 Sw 7news station).

How hot do summers get in Denver, CO?

The average high peaks at 91 °F in July, with about 64 days a year at 90 °F or more.

What kind of soil does 80261 have?

The USDA soil survey maps Vona at the center of ZIP 80261: sandy loam, well drained, pH about 7.2 (neutral).

Did spring come early in Denver, CO in 2026?

Spring leaf-out near 80261 came on Feb 19 in 2026, 25 days earlier than the 1991–2020 average (Mar 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Denver, CO?

Intermediate onions: the longest day near 80261 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 80261 change?

Yes. The 2012 USDA map put 80261 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.