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

Planting zone for 80804 — Arriba, CO

ZIP code 80804 (Arriba, Lincoln County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 5 and the first fall frost October 8.

Where ZIP 80804 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 5

First frostOct 8

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 Arriba, 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 Arriba, CO

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 5median — 50% chance of a later frost

Safe for tender plantsMay 20only 10% chance of frost after

First fall frostOctober 8median — 10% chance by Sep 27

Growing season155 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 26 and returns around October 16.

From the NOAA station Flagler 1s, CO — 11 miles away, elevation 4,922 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 80804

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 24 – Apr 7

SpinachSow outdoors · Mar 24 – Apr 14

Broccoli, cabbageStart indoors · Feb 24 – Mar 10

Broccoli, cabbageTransplant · Apr 14 – Apr 28

Onion setsPlant outdoors · Apr 7 – Apr 21

PotatoesPlant outdoors · Apr 14 – Apr 28

LettuceSow outdoors · Apr 7 – Apr 21

Carrots, beetsSow outdoors · Apr 14 – Apr 28

TomatoesStart indoors · Mar 10 – Mar 24

TomatoesTransplant · May 12 – May 26

Peppers, eggplantStart indoors · Feb 24 – Mar 10

Peppers, eggplantTransplant · May 19 – Jun 2

BeansSow outdoors · May 12 – May 26

Sweet cornSow outdoors · May 12 – May 26

Cucumbers, squashSow outdoors · May 12 – May 26

Fall lettuce, spinachSow outdoors · Aug 13 – Aug 27

GarlicPlant cloves · Sep 24 – Oct 29

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 5) and first fall frost (Oct 8) 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 80804 came on Mar 2 — 26 days earlier than the 1991–2020 average (Mar 28).

average
Mar 282026
Mar 2

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).

Soil in Arriba, CO

The soil mapped at the center of ZIP 80804 is Platner — loam, well drained.

TextureLoama good balance for most vegetables

pH7.2neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Platner loam, 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 80804; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Arriba, CO

Summer high89 °Faverage high, July

Winter low17 °Faverage low, January

Hot days43days a year at 90 °F or more

Freezing nights167nights a year at 32 °F or less

Growing degree days3,051base 50 °F — the season’s usable heat

Longest day14 h 57 mindaylight on June 21

Shortest day9 h 23 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

Snowfall25 inper year; 12 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Flagler 1s, CO (11 mi away); precipitation: Flagler 1s, CO (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 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 80804

What planting zone is ZIP code 80804?

ZIP code 80804 (Arriba, 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 Arriba, CO?

The median last spring frost (32 °F) near 80804 is May 5; after May 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Flagler 1s station.

When is the first frost in Arriba, CO?

The median first fall frost near 80804 is October 8, giving a median frost-free growing season of 155 days.

When should I plant tomatoes in 80804?

Start tomato seeds indoors around Mar 10 – Mar 24 and set transplants outside around May 12 – May 26, one to three weeks after the median last frost.

How much rain and snow does 80804 get?

About 16.5 inches of precipitation a year and 25 inches of snowfall (NOAA 1991–2020 normals, Flagler 1s station).

How hot do summers get in Arriba, CO?

The average high peaks at 89 °F in July, with about 43 days a year at 90 °F or more.

What kind of soil does 80804 have?

The USDA soil survey maps Platner at the center of ZIP 80804: loam, well drained, pH about 7.2 (neutral).

Did spring come early in Arriba, CO in 2026?

Spring leaf-out near 80804 came on Mar 2 in 2026, 26 days earlier than the 1991–2020 average (Mar 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Arriba, CO?

Intermediate onions: the longest day near 80804 is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 80804 change?

Yes. The 2012 USDA map put 80804 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.