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

Planting zone for 81133 — Fort Garland, CO

ZIP code 81133 (Fort Garland, Costilla County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 25 and the first fall frost September 22.

Where ZIP 81133 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 25
First frostSep 22
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 Fort Garland, 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 Fort Garland, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 25median — 50% chance of a later frost
Safe for tender plantsJune 12only 10% chance of frost after
First fall frostSeptember 22median — 10% chance by Sep 10
Growing season117 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 13 and returns around October 1.

From the NOAA station Blanca 4 Nw, CO — 14 miles away, elevation 7,710 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 81133

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 13 – Apr 27
SpinachSow outdoors · Apr 13 – May 4
Broccoli, cabbageStart indoors · Mar 16 – Mar 30
Broccoli, cabbageTransplant · May 4 – May 18
Onion setsPlant outdoors · Apr 27 – May 11
PotatoesPlant outdoors · May 4 – May 18
LettuceSow outdoors · Apr 27 – May 11
Carrots, beetsSow outdoors · May 4 – May 18
TomatoesStart indoors · Mar 30 – Apr 13
TomatoesTransplant · Jun 1 – Jun 15
Peppers, eggplantStart indoors · Mar 16 – Mar 30
Peppers, eggplantTransplant · Jun 8 – Jun 22
BeansSow outdoors · Jun 1 – Jun 15
Sweet cornSow outdoors · Jun 1 – Jun 15
Cucumbers, squashSow outdoors · Jun 1 – Jun 15
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 25) 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 81133 came on Mar 23 — 26 days earlier than the 1991–2020 average (Apr 18).

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

American elm120 ft · blooms early spring · medium shade tolerance · to −46 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblack walnut100 ft · blooms late spring · high shade tolerance · to −28 °Fblack willow100 ft · blooms early spring · high shade tolerance · to −58 °Fblue spruce100 ft · blooms late spring · medium shade tolerance · to −38 °F

Shrubs 98

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FApache plume6 ft · blooms late spring · high shade tolerance · to −23 °F

Wildflowers & perennials 246

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine aster0.3 ft · blooms early summer · medium shade tolerance · to −28 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °F

Grasses 163

Alaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAlpine Meadow-Foxtail0.5 ft · blooms mid spring · medium shade tolerance · to −33 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °F

Vines 3

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

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 Fort Garland, CO.

Soil in Fort Garland, CO

The soil mapped at the center of ZIP 81133 is Uracca — very cobbly sandy loam, well drained.

TextureVery cobbly sandy loamdrains and warms fast; dries out and needs more feeding
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Uracca-Culebra complex, 5 to 50 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 81133; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fort Garland, CO

Summer high83 °Faverage high, July
Winter low4 °Faverage low, January
Hot days5days a year at 90 °F or more
Freezing nights215nights a year at 32 °F or less
Growing degree days1,625base 50 °F — the season’s usable heat
Longest day14 h 45 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
Precipitation22.3 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 37 °F, low 4 °F 37°4° JanFebruary: average high 42 °F, low 10 °F 42°10° FebMarch: average high 52 °F, low 20 °F 52°20° MarApril: average high 59 °F, low 26 °F 59°26° AprMay: average high 68 °F, low 35 °F 68°35° MayJune: average high 78 °F, low 44 °F 78°44° JunJuly: average high 83 °F, low 49 °F 83°49° JulAugust: average high 80 °F, low 47 °F 80°47° AugSeptember: average high 75 °F, low 39 °F 75°39° SepOctober: average high 63 °F, low 28 °F 63°28° OctNovember: average high 49 °F, low 15 °F 49°15° NovDecember: average high 36 °F, low 5 °F 36°5° Dec

Precipitation by month inches

0″1″2″3″January: 1.55 in precipitation 1.6 JanFebruary: 1.77 in precipitation 1.8 FebMarch: 2.45 in precipitation 2.5 MarApril: 2.88 in precipitation 2.9 AprMay: 1.80 in precipitation 1.8 MayJune: 0.94 in precipitation 0.9 JunJuly: 1.73 in precipitation 1.7 JulAugust: 2.14 in precipitation 2.1 AugSeptember: 1.69 in precipitation 1.7 SepOctober: 1.64 in precipitation 1.6 OctNovember: 1.90 in precipitation 1.9 NovDecember: 1.85 in precipitation 1.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Blanca 4 Nw, CO (14 mi away); precipitation: Trinchera, CO (9 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.

810556a
La Veta, CO · 12 mi
811235a
Blanca, CO · 13 mi
811265b
Chama, CO · 20 mi
811525b
San Luis, CO · 22 mi
811465a
Mosca, CO · 23 mi
810406a
Gardner, CO · 24 mi
811515a
Sanford, CO · 26 mi
811014b
Alamosa, CO · 29 mi

Colorado planting zones →

Questions about 81133

What planting zone is ZIP code 81133?

ZIP code 81133 (Fort Garland, 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 Fort Garland, CO?

The median last spring frost (32 °F) near 81133 is May 25; after June 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Blanca 4 Nw station.

When is the first frost in Fort Garland, CO?

The median first fall frost near 81133 is September 22, giving a median frost-free growing season of 117 days.

When should I plant tomatoes in 81133?

Start tomato seeds indoors around Mar 30 – Apr 13 and set transplants outside around Jun 1 – Jun 15, one to three weeks after the median last frost.

How much rain and snow does 81133 get?

About 22.3 inches of precipitation a year (NOAA 1991–2020 normals, Trinchera station).

How hot do summers get in Fort Garland, CO?

The average high peaks at 83 °F in July, with about 5 days a year at 90 °F or more.

What kind of soil does 81133 have?

The USDA soil survey maps Uracca at the center of ZIP 81133: very cobbly sandy loam, well drained, pH about 7.2 (neutral).

Did spring come early in Fort Garland, CO in 2026?

Spring leaf-out near 81133 came on Mar 23 in 2026, 26 days earlier than the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Fort Garland, CO?

Intermediate onions: the longest day near 81133 is 14 h 45 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 81133 change?

Yes. The 2012 USDA map put 81133 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.