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

Planting zone for 81122 — Bayfield, CO

ZIP code 81122 (Bayfield, La Plata County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 31 and the first fall frost September 26.

Where ZIP 81122 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 31
First frostSep 26
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Bayfield, 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 Bayfield, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 31median — 50% chance of a later frost
Safe for tender plantsJune 14only 10% chance of frost after
First fall frostSeptember 26median — 10% chance by Sep 14
Growing season119 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 14 and returns around October 5.

From the NOAA station Vallecito Dam, CO — 6 miles away, elevation 7,645 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 81122

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 19 – May 3
SpinachSow outdoors · Apr 19 – May 10
Broccoli, cabbageStart indoors · Mar 22 – Apr 5
Broccoli, cabbageTransplant · May 10 – May 24
Onion setsPlant outdoors · May 3 – May 17
PotatoesPlant outdoors · May 10 – May 24
LettuceSow outdoors · May 3 – May 17
Carrots, beetsSow outdoors · May 10 – May 24
TomatoesStart indoors · Apr 5 – Apr 19
TomatoesTransplant · Jun 7 – Jun 21
Peppers, eggplantStart indoors · Mar 22 – Apr 5
Peppers, eggplantTransplant · Jun 14 – Jun 28
BeansSow outdoors · Jun 7 – Jun 21
Sweet cornSow outdoors · Jun 7 – Jun 21
Cucumbers, squashSow outdoors · Jun 7 – Jun 21
Fall lettuce, spinachSow outdoors · Aug 1 – Aug 15
GarlicPlant cloves · Sep 12 – Oct 17
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 31) and first fall frost (Sep 26) 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 81122 came on Mar 21 — 24 days earlier than the 1991–2020 average (Apr 14).

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

Shrubs 104

Wildflowers & perennials 251

Grasses 167

Vines 4

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 Bayfield, CO.

Soil in Bayfield, CO

The soil mapped at the center of ZIP 81122 is Carracas — loam, well drained.

TextureLoama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Carracas loam, 25 to 65 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 81122; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bayfield, CO

Summer high81 °Faverage high, July
Winter low7 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights212nights a year at 32 °F or less
Growing degree days1,491base 50 °F — the season’s usable heat
Longest day14 h 44 mindaylight on June 21
Shortest day9 h 35 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation21.4 inper year, rain and melted snow
Snowfall93 inper year; 88 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 38 °F, low 7 °F 38°7° JanFebruary: average high 41 °F, low 11 °F 41°11° FebMarch: average high 49 °F, low 20 °F 49°20° MarApril: average high 57 °F, low 27 °F 57°27° AprMay: average high 66 °F, low 35 °F 66°35° MayJune: average high 77 °F, low 42 °F 77°42° JunJuly: average high 81 °F, low 49 °F 81°49° JulAugust: average high 79 °F, low 48 °F 79°48° AugSeptember: average high 73 °F, low 40 °F 73°40° SepOctober: average high 61 °F, low 30 °F 61°30° OctNovember: average high 48 °F, low 21 °F 48°21° NovDecember: average high 39 °F, low 12 °F 39°12° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 2.09 in precipitation, 24.3 in snowfall 2.1❄24 JanFebruary: 1.89 in precipitation, 24.9 in snowfall 1.9❄25 FebMarch: 1.48 in precipitation, 6.9 in snowfall 1.5❄7 MarApril: 1.32 in precipitation, 3.9 in snowfall 1.3❄4 AprMay: 1.40 in precipitation, 1.7 in snowfall 1.4❄2 MayJune: 0.76 in precipitation 0.8 JunJuly: 1.90 in precipitation 1.9 JulAugust: 2.17 in precipitation 2.2 AugSeptember: 3.02 in precipitation 3.0 SepOctober: 2.13 in precipitation, 0.8 in snowfall 2.1❄1 OctNovember: 1.55 in precipitation, 5.9 in snowfall 1.6❄6 NovDecember: 1.73 in precipitation, 25 in snowfall 1.7❄25 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Vallecito Dam, CO (6 mi away); precipitation: Bayfield 6.2 N, CO (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

6 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 81122

What planting zone is ZIP code 81122?

ZIP code 81122 (Bayfield, 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 Bayfield, CO?

The median last spring frost (32 °F) near 81122 is May 31; after June 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Vallecito Dam station.

When is the first frost in Bayfield, CO?

The median first fall frost near 81122 is September 26, giving a median frost-free growing season of 119 days.

When should I plant tomatoes in 81122?

Start tomato seeds indoors around Apr 5 – Apr 19 and set transplants outside around Jun 7 – Jun 21, one to three weeks after the median last frost.

How much rain and snow does 81122 get?

About 21.4 inches of precipitation a year and 93 inches of snowfall (NOAA 1991–2020 normals, Bayfield 6.2 N station).

How hot do summers get in Bayfield, CO?

The average high peaks at 81 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 81122 have?

The USDA soil survey maps Carracas at the center of ZIP 81122: loam, well drained, pH about 6.5 (neutral).

Did spring come early in Bayfield, CO in 2026?

Spring leaf-out near 81122 came on Mar 21 in 2026, 24 days earlier than the 1991–2020 average (Apr 14), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bayfield, CO?

Intermediate onions: the longest day near 81122 is 14 h 44 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 81122 change?

Yes. The 2012 USDA map put 81122 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.