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

Planting zone for 80453 — Idledale, CO

ZIP code 80453 (Idledale, Jefferson County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 23 and the first fall frost September 22.

Where ZIP 80453 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostMay 23

First frostSep 22

2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Idledale, 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 Idledale, CO

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 23median — 50% chance of a later frost

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

First fall frostSeptember 22median — 10% chance by Sep 6

Growing season118 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 9 and returns around October 2.

From the NOAA station Evergreen, CO — 4 miles away, elevation 6,985 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 80453

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 11 – Apr 25

SpinachSow outdoors · Apr 11 – May 2

Broccoli, cabbageStart indoors · Mar 14 – Mar 28

Broccoli, cabbageTransplant · May 2 – May 16

Onion setsPlant outdoors · Apr 25 – May 9

PotatoesPlant outdoors · May 2 – May 16

LettuceSow outdoors · Apr 25 – May 9

Carrots, beetsSow outdoors · May 2 – May 16

TomatoesStart indoors · Mar 28 – Apr 11

TomatoesTransplant · May 30 – Jun 13

Peppers, eggplantStart indoors · Mar 14 – Mar 28

Peppers, eggplantTransplant · Jun 6 – Jun 20

BeansSow outdoors · May 30 – Jun 13

Sweet cornSow outdoors · May 30 – Jun 13

Cucumbers, squashSow outdoors · May 30 – Jun 13

Fall lettuce, spinachSow outdoors · Jul 28 – Aug 11

GarlicPlant cloves · Sep 8 – Oct 13

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 23) and first fall frost (Sep 22) 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 80453 came on Mar 6 — 31 days earlier than the 1991–2020 average (Apr 6).

average
Apr 62026
Mar 6

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 5b in Colorado

546 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. 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 Idledale, CO.

Soil in Idledale, CO

The soil mapped at the center of ZIP 80453 is Cryofluvents — variable, well drained.

TextureVariabletop layer

DrainageWell drainednatural drainage class

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Cryofluvents, 0 to 5 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 80453; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Idledale, CO

Summer high81 °Faverage high, July

Winter low13 °Faverage low, January

Hot days6days a year at 90 °F or more

Freezing nights215nights a year at 32 °F or less

Growing degree days1,514base 50 °F — the season’s usable heat

Longest day14 h 59 mindaylight on June 21

Shortest day9 h 22 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation22.2 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: Evergreen, CO (4 mi away); precipitation: Kittredge 2.5 Sse, CO (4 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.

804545b

Indian Hills, CO · 2 mi

Colorado planting zones →

Questions about 80453

What planting zone is ZIP code 80453?

ZIP code 80453 (Idledale, CO) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Idledale, CO?

The median last spring frost (32 °F) near 80453 is May 23; after June 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Evergreen station.

When is the first frost in Idledale, CO?

The median first fall frost near 80453 is September 22, giving a median frost-free growing season of 118 days.

When should I plant tomatoes in 80453?

Start tomato seeds indoors around Mar 28 – Apr 11 and set transplants outside around May 30 – Jun 13, one to three weeks after the median last frost.

How much rain and snow does 80453 get?

About 22.2 inches of precipitation a year (NOAA 1991–2020 normals, Kittredge 2.5 Sse station).

How hot do summers get in Idledale, CO?

The average high peaks at 81 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 80453 have?

The USDA soil survey maps Cryofluvents at the center of ZIP 80453: variable, well drained.

Did spring come early in Idledale, CO in 2026?

Spring leaf-out near 80453 came on Mar 6 in 2026, 31 days earlier than the 1991–2020 average (Apr 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Idledale, CO?

Intermediate onions: the longest day near 80453 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.