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

Planting zone for 80127 — Littleton, CO

ZIP code 80127 (Littleton, Jefferson County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 8 and the first fall frost October 3.

Where ZIP 80127 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 8

First frostOct 3

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 Littleton, 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 Littleton, CO

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 8median — 50% chance of a later frost

Safe for tender plantsMay 22only 10% chance of frost after

First fall frostOctober 3median — 10% chance by Sep 21

Growing season147 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 29 and returns around October 13.

From the NOAA station Kassler, CO — 4 miles away, elevation 5,588 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 80127

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 27 – Apr 10

SpinachSow outdoors · Mar 27 – Apr 17

Broccoli, cabbageStart indoors · Feb 27 – Mar 13

Broccoli, cabbageTransplant · Apr 17 – May 1

Onion setsPlant outdoors · Apr 10 – Apr 24

PotatoesPlant outdoors · Apr 17 – May 1

LettuceSow outdoors · Apr 10 – Apr 24

Carrots, beetsSow outdoors · Apr 17 – May 1

TomatoesStart indoors · Mar 13 – Mar 27

TomatoesTransplant · May 15 – May 29

Peppers, eggplantStart indoors · Feb 27 – Mar 13

Peppers, eggplantTransplant · May 22 – Jun 5

BeansSow outdoors · May 15 – May 29

Sweet cornSow outdoors · May 15 – May 29

Cucumbers, squashSow outdoors · May 15 – May 29

Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22

GarlicPlant cloves · Sep 19 – Oct 24

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 3) 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 80127 came on Mar 2 — 31 days earlier than the 1991–2020 average (Apr 2).

average
Apr 22026
Mar 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 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 Littleton, CO.

Soil in Littleton, CO

The soil mapped at the center of ZIP 80127 is Ratake — stony sandy loam, well drained.

TextureStony sandy loamdrains and warms fast; dries out and needs more feeding

pH7.0neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Ratake-Cathedral-Rock outcrop complex, 25 to 60 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 80127; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Littleton, CO

Summer high87 °Faverage high, July

Winter low17 °Faverage low, January

Hot days36days a year at 90 °F or more

Freezing nights156nights a year at 32 °F or less

Growing degree days2,743base 50 °F — the season’s usable heat

Longest day14 h 58 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

Precipitation20.6 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: Kassler, CO (4 mi away); precipitation: Littleton 5.7 Sw, CO (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Indian Hills, CO · 8 mi

All 16 ZIP codes in Littleton → · Colorado planting zones →

Questions about 80127

What planting zone is ZIP code 80127?

ZIP code 80127 (Littleton, 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 Littleton, CO?

The median last spring frost (32 °F) near 80127 is May 8; after May 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Kassler station.

When is the first frost in Littleton, CO?

The median first fall frost near 80127 is October 3, giving a median frost-free growing season of 147 days.

When should I plant tomatoes in 80127?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 80127 get?

About 20.6 inches of precipitation a year (NOAA 1991–2020 normals, Littleton 5.7 Sw station).

How hot do summers get in Littleton, CO?

The average high peaks at 87 °F in July, with about 36 days a year at 90 °F or more.

What kind of soil does 80127 have?

The USDA soil survey maps Ratake at the center of ZIP 80127: stony sandy loam, well drained, pH about 7.0 (neutral).

Did spring come early in Littleton, CO in 2026?

Spring leaf-out near 80127 came on Mar 2 in 2026, 31 days earlier than the 1991–2020 average (Apr 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Littleton, CO?

Intermediate onions: the longest day near 80127 is 14 h 58 min, so day-neutral types bulb best; long-day varieties may not bulb fully.