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

Planting zone for 80816 — Florissant, CO

ZIP code 80816 (Florissant, Teller County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 26 and the first fall frost September 26.

Where ZIP 80816 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.

Zone5a−20 to −15 °F

Coldest night−28.9 to −26.1 °C

Last frostMay 26

First frostSep 26

2012 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Florissant, 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 Florissant, CO

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 26median — 50% chance of a later frost

Safe for tender plantsJune 9only 10% chance of frost after

First fall frostSeptember 26median — 10% chance by Sep 13

Growing season121 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 14 and returns around October 4.

From the NOAA station Cripple Creek 3nnw, CO — 7 miles away, elevation 9,236 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 80816

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 14 – Apr 28

SpinachSow outdoors · Apr 14 – May 5

Broccoli, cabbageStart indoors · Mar 17 – Mar 31

Broccoli, cabbageTransplant · May 5 – May 19

Onion setsPlant outdoors · Apr 28 – May 12

PotatoesPlant outdoors · May 5 – May 19

LettuceSow outdoors · Apr 28 – May 12

Carrots, beetsSow outdoors · May 5 – May 19

TomatoesStart indoors · Mar 31 – Apr 14

TomatoesTransplant · Jun 2 – Jun 16

Peppers, eggplantStart indoors · Mar 17 – Mar 31

Peppers, eggplantTransplant · Jun 9 – Jun 23

BeansSow outdoors · Jun 2 – Jun 16

Sweet cornSow outdoors · Jun 2 – Jun 16

Cucumbers, squashSow outdoors · Jun 2 – Jun 16

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 26) 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 80816 came on Mar 26 — 34 days earlier than the 1991–2020 average (Apr 29).

average
Apr 292026
Mar 26

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 5a in Colorado

532 plants native to the lower 48 states, recorded in Colorado, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. 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 Florissant, CO.

Soil in Florissant, CO

The soil mapped at the center of ZIP 80816 is Cathedral — very gravelly sandy loam, well drained.

TextureVery gravelly sandy loamdrains and warms fast; dries out and needs more feeding

pH6.4slightly acidic; 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: Cathedral very gravelly sandy loam, 15 to 40 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 80816; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Florissant, CO

Summer high79 °Faverage high, July

Winter low5 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights250nights a year at 32 °F or less

Growing degree days896base 50 °F — the season’s usable heat

Longest day14 h 54 mindaylight on June 21

Shortest day9 h 26 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

Snowfall59 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Florissant Fossil Bed, CO (4 mi away); precipitation: Florissant Fossil Bed, CO (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

808145b

Divide, CO · 9 mi

808135b

Cripple Creek, CO · 13 mi

808205b

Guffey, CO · 15 mi

808275b

Lake George, CO · 16 mi

Woodland Park, CO · 17 mi

808635b

Woodland Park, CO · 19 mi

Colorado planting zones →

Questions about 80816

What planting zone is ZIP code 80816?

ZIP code 80816 (Florissant, CO) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Florissant, CO?

The median last spring frost (32 °F) near 80816 is May 26; after June 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cripple Creek 3nnw station.

When is the first frost in Florissant, CO?

The median first fall frost near 80816 is September 26, giving a median frost-free growing season of 121 days.

When should I plant tomatoes in 80816?

Start tomato seeds indoors around Mar 31 – Apr 14 and set transplants outside around Jun 2 – Jun 16, one to three weeks after the median last frost.

How much rain and snow does 80816 get?

About 15 inches of precipitation a year and 59 inches of snowfall (NOAA 1991–2020 normals, Florissant Fossil Bed station).

How hot do summers get in Florissant, CO?

The average high peaks at 79 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 80816 have?

The USDA soil survey maps Cathedral at the center of ZIP 80816: very gravelly sandy loam, well drained, pH about 6.4 (slightly acidic).

Did spring come early in Florissant, CO in 2026?

Spring leaf-out near 80816 came on Mar 26 in 2026, 34 days earlier than the 1991–2020 average (Apr 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Florissant, CO?

Intermediate onions: the longest day near 80816 is 14 h 54 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 80816 change?

Yes. The 2012 USDA map put 80816 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.