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

Planting zone for 81631 — Eagle, CO

ZIP code 81631 (Eagle, Eagle County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is June 21 and the first fall frost September 7.

Where ZIP 81631 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 frostJun 21
First frostSep 7
2012 zone5a

Was 5a on the 2012 map — half a zone warmer now. 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 Eagle, 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 Eagle, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 21median — 50% chance of a later frost
Safe for tender plantsJuly 9only 10% chance of frost after
First fall frostSeptember 7median — 10% chance by Aug 26
Growing season77 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 31 and returns around September 21.

From the NOAA station Vail, CO — 22 miles away, elevation 8,304 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 81631

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · May 10 – May 24
SpinachSow outdoors · May 10 – May 31
Broccoli, cabbageStart indoors · Apr 12 – Apr 26
Broccoli, cabbageTransplant · May 31 – Jun 14
Onion setsPlant outdoors · May 24 – Jun 7
PotatoesPlant outdoors · May 31 – Jun 14
LettuceSow outdoors · May 24 – Jun 7
Carrots, beetsSow outdoors · May 31 – Jun 14
TomatoesStart indoors · Apr 26 – May 10
TomatoesTransplant · Jun 28 – Jul 12
Peppers, eggplantStart indoors · Apr 12 – Apr 26
Peppers, eggplantTransplant · Jul 5 – Jul 19
BeansSow outdoors · Jun 28 – Jul 12
Sweet cornSow outdoors · Jun 28 – Jul 12
Cucumbers, squashSow outdoors · Jun 28 – Jul 12
Fall lettuce, spinachSow outdoors · Jul 13 – Jul 27
GarlicPlant cloves · Aug 24 – Sep 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 21) and first fall frost (Sep 7) 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 81631 came on Mar 26 — 25 days earlier than the 1991–2020 average (Apr 20).

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.

Trees 27

Shrubs 98

Wildflowers & perennials 246

Grasses 163

Vines 3

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 Eagle, CO.

Soil in Eagle, CO

The soil mapped at the center of ZIP 81631 is Yamo — loam, well drained.

TextureLoama good balance for most vegetables
pH7.9alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Yamo loam, 1 to 6 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 81631; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Eagle, CO

Summer high81 °Faverage high, July
Winter low4 °Faverage low, January
Hot days4days a year at 90 °F or more
Freezing nights272nights a year at 32 °F or less
Growing degree days916base 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
Precipitation16.5 inper year, rain and melted snow

Average high and low, by month

−10°0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 34 °F, low 4 °F 34°4° JanFebruary: average high 36 °F, low 6 °F 36°6° FebMarch: average high 43 °F, low 13 °F 43°13° MarApril: average high 51 °F, low 21 °F 51°21° AprMay: average high 63 °F, low 28 °F 63°28° MayJune: average high 75 °F, low 34 °F 75°34° JunJuly: average high 81 °F, low 40 °F 81°40° JulAugust: average high 80 °F, low 39 °F 80°39° AugSeptember: average high 71 °F, low 32 °F 71°32° SepOctober: average high 61 °F, low 23 °F 61°23° OctNovember: average high 45 °F, low 13 °F 45°13° NovDecember: average high 34 °F, low 5 °F 34°5° Dec

Precipitation by month inches

0″1″2″January: 1.05 in precipitation 1.1 JanFebruary: 1.06 in precipitation 1.1 FebMarch: 1.17 in precipitation 1.2 MarApril: 1.85 in precipitation 1.9 AprMay: 1.73 in precipitation 1.7 MayJune: 1.06 in precipitation 1.1 JunJuly: 1.74 in precipitation 1.7 JulAugust: 1.59 in precipitation 1.6 AugSeptember: 1.72 in precipitation 1.7 SepOctober: 1.42 in precipitation 1.4 OctNovember: 1.08 in precipitation 1.1 NovDecember: 1.05 in precipitation 1.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Meredith, CO (19 mi away); precipitation: Wolcott 2.3 N, CO (9 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.

Colorado planting zones →

Questions about 81631

What planting zone is ZIP code 81631?

ZIP code 81631 (Eagle, 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 Eagle, CO?

The median last spring frost (32 °F) near 81631 is June 21; after July 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Vail station.

When is the first frost in Eagle, CO?

The median first fall frost near 81631 is September 7, giving a median frost-free growing season of 77 days.

When should I plant tomatoes in 81631?

Start tomato seeds indoors around Apr 26 – May 10 and set transplants outside around Jun 28 – Jul 12, one to three weeks after the median last frost.

How much rain and snow does 81631 get?

About 16.5 inches of precipitation a year (NOAA 1991–2020 normals, Wolcott 2.3 N station).

How hot do summers get in Eagle, CO?

The average high peaks at 81 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 81631 have?

The USDA soil survey maps Yamo at the center of ZIP 81631: loam, well drained, pH about 7.9 (alkaline).

Did spring come early in Eagle, CO in 2026?

Spring leaf-out near 81631 came on Mar 26 in 2026, 25 days earlier than the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Eagle, CO?

Intermediate onions: the longest day near 81631 is 14 h 58 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 81631 change?

Yes. The 2012 USDA map put 81631 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.