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

Planting zone for 80025 — Eldorado Springs, CO

ZIP code 80025 (Eldorado Springs, Boulder County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 24 and the first fall frost September 23.

Where ZIP 80025 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 frostMay 24
First frostSep 23
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 Eldorado Springs, 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 Eldorado Springs, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 24median — 50% chance of a later frost
Safe for tender plantsJune 10only 10% chance of frost after
First fall frostSeptember 23median — 10% chance by Sep 9
Growing season120 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 10 and returns around October 3.

From the NOAA station Gross Rsvr, CO — 2 miles away, elevation 7,970 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 80025

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 12 – Apr 26
SpinachSow outdoors · Apr 12 – May 3
Broccoli, cabbageStart indoors · Mar 15 – Mar 29
Broccoli, cabbageTransplant · May 3 – May 17
Onion setsPlant outdoors · Apr 26 – May 10
PotatoesPlant outdoors · May 3 – May 17
LettuceSow outdoors · Apr 26 – May 10
Carrots, beetsSow outdoors · May 3 – May 17
TomatoesStart indoors · Mar 29 – Apr 12
TomatoesTransplant · May 31 – Jun 14
Peppers, eggplantStart indoors · Mar 15 – Mar 29
Peppers, eggplantTransplant · Jun 7 – Jun 21
BeansSow outdoors · May 31 – Jun 14
Sweet cornSow outdoors · May 31 – Jun 14
Cucumbers, squashSow outdoors · May 31 – Jun 14
Fall lettuce, spinachSow outdoors · Jul 29 – Aug 12
GarlicPlant cloves · Sep 9 – Oct 14
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 24) and first fall frost (Sep 23) 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 80025 came on Mar 5 — 28 days earlier than the 1991–2020 average (Apr 2).

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 Eldorado Springs, CO.

Soil in Eldorado Springs, CO

The soil mapped at the center of ZIP 80025 is Littlejames — very gravelly coarse sandy loam, excessively drained.

TextureVery gravelly coarse sandy loamdrains and warms fast; dries out and needs more feeding
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter4%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Rock outcrop-Littlejames extremely bouldery-Lefthand, very stony complex, 25 to 70 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 80025; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Eldorado Springs, CO

Summer high79 °Faverage high, July
Winter low17 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights188nights a year at 32 °F or less
Growing degree days1,402base 50 °F — the season’s usable heat
Longest day15 h 00 mindaylight on June 21
Shortest day9 h 20 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation20.3 inper year, rain and melted snow
Snowfall99 inper year; 87 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 39 °F, low 17 °F 39°17° JanFebruary: average high 40 °F, low 17 °F 40°17° FebMarch: average high 47 °F, low 22 °F 47°22° MarApril: average high 52 °F, low 27 °F 52°27° AprMay: average high 61 °F, low 35 °F 61°35° MayJune: average high 73 °F, low 44 °F 73°44° JunJuly: average high 79 °F, low 50 °F 79°50° JulAugust: average high 77 °F, low 48 °F 77°48° AugSeptember: average high 70 °F, low 41 °F 70°41° SepOctober: average high 57 °F, low 31 °F 57°31° OctNovember: average high 47 °F, low 24 °F 47°24° NovDecember: average high 40 °F, low 18 °F 40°18° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.71 in precipitation, 9.4 in snowfall 0.7❄9 JanFebruary: 0.90 in precipitation, 14 in snowfall 0.9❄14 FebMarch: 1.94 in precipitation, 21 in snowfall 1.9❄21 MarApril: 2.73 in precipitation, 19.8 in snowfall 2.7❄20 AprMay: 2.89 in precipitation, 3.9 in snowfall 2.9❄4 MayJune: 1.87 in precipitation, 0.1 in snowfall 1.9 JunJuly: 2.04 in precipitation 2.0 JulAugust: 2.12 in precipitation 2.1 AugSeptember: 1.99 in precipitation, 0.9 in snowfall 2.0❄1 SepOctober: 1.35 in precipitation, 6.9 in snowfall 1.4❄7 OctNovember: 0.96 in precipitation, 12 in snowfall 1.0❄12 NovDecember: 0.78 in precipitation, 11.1 in snowfall 0.8❄11 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Gross Rsvr, CO (2 mi away); precipitation: Gross Rsvr, CO (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

803056a
Boulder, CO · 4 mi
803106a
Boulder, CO · 6 mi
803036a
Boulder, CO · 6 mi
804715b
Pinecliffe, CO · 6 mi
800076a
Arvada, CO · 7 mi
804035b
Golden, CO · 7 mi
803026a
Boulder, CO · 7 mi
800276a
Louisville, CO · 8 mi

Colorado planting zones →

Questions about 80025

What planting zone is ZIP code 80025?

ZIP code 80025 (Eldorado Springs, 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 Eldorado Springs, CO?

The median last spring frost (32 °F) near 80025 is May 24; after June 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Gross Rsvr station.

When is the first frost in Eldorado Springs, CO?

The median first fall frost near 80025 is September 23, giving a median frost-free growing season of 120 days.

When should I plant tomatoes in 80025?

Start tomato seeds indoors around Mar 29 – Apr 12 and set transplants outside around May 31 – Jun 14, one to three weeks after the median last frost.

How much rain and snow does 80025 get?

About 20.3 inches of precipitation a year and 99 inches of snowfall (NOAA 1991–2020 normals, Gross Rsvr station).

How hot do summers get in Eldorado Springs, CO?

The average high peaks at 79 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 80025 have?

The USDA soil survey maps Littlejames at the center of ZIP 80025: very gravelly coarse sandy loam, excessively drained, pH about 6.2 (slightly acidic).

Did spring come early in Eldorado Springs, CO in 2026?

Spring leaf-out near 80025 came on Mar 5 in 2026, 28 days earlier than the 1991–2020 average (Apr 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Eldorado Springs, CO?

Long-day onions: the longest day near 80025 is 15 h 00 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).