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

Planting zone for 80040 — Aurora, CO

ZIP code 80040 (Aurora, Adams County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 4 and the first fall frost October 8.

Where ZIP 80040 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 frostMay 4
First frostOct 8
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Aurora, 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 Aurora, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 4median — 50% chance of a later frost
Safe for tender plantsMay 16only 10% chance of frost after
First fall frostOctober 8median — 10% chance by Sep 25
Growing season156 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 22 and returns around October 18.

From the NOAA station Denver-Stapleton, CO — 3 miles away, elevation 5,286 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 80040

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 23 – Apr 6
SpinachSow outdoors · Mar 23 – Apr 13
Broccoli, cabbageStart indoors · Feb 23 – Mar 9
Broccoli, cabbageTransplant · Apr 13 – Apr 27
Onion setsPlant outdoors · Apr 6 – Apr 20
PotatoesPlant outdoors · Apr 13 – Apr 27
LettuceSow outdoors · Apr 6 – Apr 20
Carrots, beetsSow outdoors · Apr 13 – Apr 27
TomatoesStart indoors · Mar 9 – Mar 23
TomatoesTransplant · May 11 – May 25
Peppers, eggplantStart indoors · Feb 23 – Mar 9
Peppers, eggplantTransplant · May 18 – Jun 1
BeansSow outdoors · May 11 – May 25
Sweet cornSow outdoors · May 11 – May 25
Cucumbers, squashSow outdoors · May 11 – May 25
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 4) 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 80040 came on Feb 19 — 28 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 Aurora, CO.

Soil in Aurora, CO

The soil mapped at the center of ZIP 80040 is Fondis — 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 matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Fondis silt loam, 1 to 3 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 80040; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Aurora, CO

Summer high90 °Faverage high, July
Winter low18 °Faverage low, January
Hot days42days a year at 90 °F or more
Freezing nights156nights a year at 32 °F or less
Growing degree days3,011base 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
Precipitation16.3 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 47 °F, low 18 °F 47°18° JanFebruary: average high 48 °F, low 19 °F 48°19° FebMarch: average high 56 °F, low 27 °F 56°27° MarApril: average high 63 °F, low 34 °F 63°34° AprMay: average high 72 °F, low 43 °F 72°43° MayJune: average high 84 °F, low 53 °F 84°53° JunJuly: average high 90 °F, low 59 °F 90°59° JulAugust: average high 88 °F, low 57 °F 88°57° AugSeptember: average high 80 °F, low 48 °F 80°48° SepOctober: average high 67 °F, low 36 °F 67°36° OctNovember: average high 55 °F, low 26 °F 55°26° NovDecember: average high 46 °F, low 18 °F 46°18° Dec

Precipitation by month inches

0″1″2″3″January: 0.49 in precipitation 0.5 JanFebruary: 0.75 in precipitation 0.8 FebMarch: 1.17 in precipitation 1.2 MarApril: 1.85 in precipitation 1.9 AprMay: 2.55 in precipitation 2.5 MayJune: 1.72 in precipitation 1.7 JunJuly: 2.02 in precipitation 2.0 JulAugust: 1.98 in precipitation 2.0 AugSeptember: 1.35 in precipitation 1.4 SepOctober: 1.12 in precipitation 1.1 OctNovember: 0.68 in precipitation 0.7 NovDecember: 0.57 in precipitation 0.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Denver-Stapleton, CO (3 mi away); precipitation: Aurora 4.2 Nnw, CO (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

800426a
Aurora, CO · <1 mi
800456a
Aurora, CO · 1 mi
802016a
Denver, CO · 1 mi
800106a
Aurora, CO · 2 mi
800126a
Aurora, CO · 2 mi
800116a
Aurora, CO · 2 mi
802306a
Denver, CO · 3 mi
802476a
Denver, CO · 3 mi

All 17 ZIP codes in Aurora → · Colorado planting zones →

Questions about 80040

What planting zone is ZIP code 80040?

ZIP code 80040 (Aurora, 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 Aurora, CO?

The median last spring frost (32 °F) near 80040 is May 4; after May 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Denver-Stapleton station.

When is the first frost in Aurora, CO?

The median first fall frost near 80040 is October 8, giving a median frost-free growing season of 156 days.

When should I plant tomatoes in 80040?

Start tomato seeds indoors around Mar 9 – Mar 23 and set transplants outside around May 11 – May 25, one to three weeks after the median last frost.

How much rain and snow does 80040 get?

About 16.3 inches of precipitation a year (NOAA 1991–2020 normals, Aurora 4.2 Nnw station).

How hot do summers get in Aurora, CO?

The average high peaks at 90 °F in July, with about 42 days a year at 90 °F or more.

What kind of soil does 80040 have?

The USDA soil survey maps Fondis at the center of ZIP 80040: silt loam, well drained, pH about 7.2 (neutral).

Did spring come early in Aurora, CO in 2026?

Spring leaf-out near 80040 came on Feb 19 in 2026, 28 days earlier than the 1991–2020 average (Mar 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Aurora, CO?

Intermediate onions: the longest day near 80040 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.