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

Planting zone for Usaf Academy, CO

Usaf Academy, CO is in USDA zone 5b across its 2 ZIP codes. The median last spring frost is May 17 and the first fall frost October 1.

Usaf Academy on the zone map

Outlined: its 1 ZIP code areas · 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
ZIP codes2
Last frostMay 17
First frostOct 1
Growing season136 days

5b 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Usaf Academy, 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 Usaf Academy, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 17median — 50% chance of a later frost
Safe for tender plantsMay 30only 10% chance of frost after
First fall frostOctober 1median — 10% chance by Sep 19
Growing season136 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 6 and returns around October 9.

From the NOAA station Monument 3s, CO, elevation 6,821 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 Usaf Academy

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 5 – Apr 19
SpinachSow outdoors · Apr 5 – Apr 26
Broccoli, cabbageStart indoors · Mar 8 – Mar 22
Broccoli, cabbageTransplant · Apr 26 – May 10
Onion setsPlant outdoors · Apr 19 – May 3
PotatoesPlant outdoors · Apr 26 – May 10
LettuceSow outdoors · Apr 19 – May 3
Carrots, beetsSow outdoors · Apr 26 – May 10
TomatoesStart indoors · Mar 22 – Apr 5
TomatoesTransplant · May 24 – Jun 7
Peppers, eggplantStart indoors · Mar 8 – Mar 22
Peppers, eggplantTransplant · May 31 – Jun 14
BeansSow outdoors · May 24 – Jun 7
Sweet cornSow outdoors · May 24 – Jun 7
Cucumbers, squashSow outdoors · May 24 – Jun 7
Fall lettuce, spinachSow outdoors · Aug 6 – Aug 20
GarlicPlant cloves · Sep 17 – Oct 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 17) and first fall frost (Oct 1) 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 80841 came on Mar 5 — 26 days earlier than the 1991–2020 average (Mar 31).

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 Usaf Academy, CO.

Soil in Usaf Academy, CO

The soil mapped at the center of ZIP 80841 is Platner — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Platner-Ascalon sandy loams, 0 to 3 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 80841; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Usaf Academy, CO

Summer high86 °Faverage high, July
Winter low15 °Faverage low, January
Hot days22days a year at 90 °F or more
Freezing nights177nights a year at 32 °F or less
Growing degree days2,436base 50 °F — the season’s usable heat
Longest day14 h 55 mindaylight on June 21
Shortest day9 h 25 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation15 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 15 °F 43°15° JanFebruary: average high 45 °F, low 16 °F 45°16° FebMarch: average high 54 °F, low 24 °F 54°24° MarApril: average high 61 °F, low 30 °F 61°30° AprMay: average high 70 °F, low 40 °F 70°40° MayJune: average high 81 °F, low 50 °F 81°50° JunJuly: average high 86 °F, low 56 °F 86°56° JulAugust: average high 84 °F, low 54 °F 84°54° AugSeptember: average high 77 °F, low 45 °F 77°45° SepOctober: average high 64 °F, low 34 °F 64°34° OctNovember: average high 50 °F, low 24 °F 50°24° NovDecember: average high 42 °F, low 15 °F 42°15° Dec

Precipitation by month inches

0″1″2″3″January: 0.27 in precipitation 0.3 JanFebruary: 0.36 in precipitation 0.4 FebMarch: 0.80 in precipitation 0.8 MarApril: 1.37 in precipitation 1.4 AprMay: 2.21 in precipitation 2.2 MayJune: 2.20 in precipitation 2.2 JunJuly: 2.53 in precipitation 2.5 JulAugust: 2.72 in precipitation 2.7 AugSeptember: 0.96 in precipitation 1.0 SepOctober: 0.84 in precipitation 0.8 OctNovember: 0.40 in precipitation 0.4 NovDecember: 0.31 in precipitation 0.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Matheson 8 Se, CO (3 mi away); precipitation: Limon Wsmo, CO (9 mi away). Daylight is calculated from latitude.

ZIP codes in Usaf Academy

808405b
−15 to −10 °F
808415b
−15 to −10 °F

Colorado planting zones →

Questions about Usaf Academy

What planting zone is Usaf Academy, CO?

Usaf Academy, CO is in USDA hardiness zone 5b on the 2023 map (5b: −15 to −10 °F).

When is the last frost in Usaf Academy, CO?

The median last spring frost is May 17 and the median first fall frost is October 1 (NOAA 1991–2020 normals, Monument 3s station).

When can I plant a garden in Usaf Academy, CO?

Cool-season crops like peas and spinach go in around Apr 5 – Apr 26; tomatoes, peppers, beans and squash after about May 24, once frost risk has passed.

What kind of onions grow in Usaf Academy, CO?

Intermediate onions: the longest day is 14 h 55 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Usaf Academy, CO get?

About 15 inches of precipitation a year (NOAA 1991–2020 normals).