Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 80476 — Silver Plume, CO

ZIP code 80476 (Silver Plume, Clear Creek County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is June 6 and the first fall frost September 19.

Where ZIP 80476 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.

Zone5a−20 to −15 °F

Coldest night−28.9 to −26.1 °C

Last frostJun 6

First frostSep 19

2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Silver Plume, 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 Silver Plume, CO

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostJune 6median — 50% chance of a later frost

Safe for tender plantsJune 21only 10% chance of frost after

First fall frostSeptember 19median — 10% chance by Sep 5

Growing season103 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 25 and returns around September 26.

From the NOAA station Cabin Creek, CO — 7 miles away, elevation 10,020 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 80476

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 25 – May 9

SpinachSow outdoors · Apr 25 – May 16

Broccoli, cabbageStart indoors · Mar 28 – Apr 11

Broccoli, cabbageTransplant · May 16 – May 30

Onion setsPlant outdoors · May 9 – May 23

PotatoesPlant outdoors · May 16 – May 30

LettuceSow outdoors · May 9 – May 23

Carrots, beetsSow outdoors · May 16 – May 30

TomatoesStart indoors · Apr 11 – Apr 25

TomatoesTransplant · Jun 13 – Jun 27

Peppers, eggplantStart indoors · Mar 28 – Apr 11

Peppers, eggplantTransplant · Jun 20 – Jul 4

BeansSow outdoors · Jun 13 – Jun 27

Sweet cornSow outdoors · Jun 13 – Jun 27

Cucumbers, squashSow outdoors · Jun 13 – Jun 27

Fall lettuce, spinachSow outdoors · Jul 25 – Aug 8

GarlicPlant cloves · Sep 5 – Oct 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 6) and first fall frost (Sep 19) 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 80476 came on May 26 — 4 days earlier than the 1991–2020 average (May 30).

average
May 302026
May 26

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 5a in Colorado

532 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

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 Silver Plume, CO.

Soil in Silver Plume, CO

The soil mapped at the center of ZIP 80476 is Leighcan family — cobbly silt loam, somewhat excessively drained.

TextureCobbly silt loama good balance for most vegetables

pH6.0slightly acidic; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter1%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Leighcan family, till substratum, 40 to 75 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 80476; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Silver Plume, CO

Summer high69 °Faverage high, July

Winter low12 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights234nights a year at 32 °F or less

Growing degree days612base 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

Precipitation31.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cabin Creek, CO (7 mi away); precipitation: Grizzly Peak, CO (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

804385a

Empire, CO · 5 mi

804445a

Georgetown, CO · 6 mi

Idaho Springs, CO · 13 mi

804485b

Grant, CO · 13 mi

804974b

Silverthorne, CO · 15 mi

804825a

Winter Park, CO · 16 mi

Colorado planting zones →

Questions about 80476

What planting zone is ZIP code 80476?

ZIP code 80476 (Silver Plume, CO) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Silver Plume, CO?

The median last spring frost (32 °F) near 80476 is June 6; after June 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cabin Creek station.

When is the first frost in Silver Plume, CO?

The median first fall frost near 80476 is September 19, giving a median frost-free growing season of 103 days.

When should I plant tomatoes in 80476?

Start tomato seeds indoors around Apr 11 – Apr 25 and set transplants outside around Jun 13 – Jun 27, one to three weeks after the median last frost.

How much rain and snow does 80476 get?

About 31.5 inches of precipitation a year (NOAA 1991–2020 normals, Grizzly Peak station).

How hot do summers get in Silver Plume, CO?

The average high peaks at 69 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 80476 have?

The USDA soil survey maps Leighcan family at the center of ZIP 80476: cobbly silt loam, somewhat excessively drained, pH about 6.0 (slightly acidic).

Did spring come early in Silver Plume, CO in 2026?

Spring leaf-out near 80476 came on May 26 in 2026, 4 days earlier than the 1991–2020 average (May 30), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Silver Plume, CO?

Intermediate onions: the longest day near 80476 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.