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

Planting zone for 81077 — Swink, CO

ZIP code 81077 (Swink, Otero County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 26 and the first fall frost October 15.

Where ZIP 81077 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 frostApr 26
First frostOct 15
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 Swink, 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 Swink, CO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 26median — 50% chance of a later frost
Safe for tender plantsMay 9only 10% chance of frost after
First fall frostOctober 15median — 10% chance by Oct 3
Growing season171 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 24.

From the NOAA station La Junta, CO — 4 miles away, elevation 4,088 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 81077

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 15 – Mar 29
SpinachSow outdoors · Mar 15 – Apr 5
Broccoli, cabbageStart indoors · Feb 15 – Mar 1
Broccoli, cabbageTransplant · Apr 5 – Apr 19
Onion setsPlant outdoors · Mar 29 – Apr 12
PotatoesPlant outdoors · Apr 5 – Apr 19
LettuceSow outdoors · Mar 29 – Apr 12
Carrots, beetsSow outdoors · Apr 5 – Apr 19
TomatoesStart indoors · Mar 1 – Mar 15
TomatoesTransplant · May 3 – May 17
Peppers, eggplantStart indoors · Feb 15 – Mar 1
Peppers, eggplantTransplant · May 10 – May 24
BeansSow outdoors · May 3 – May 17
Sweet cornSow outdoors · May 3 – May 17
Cucumbers, squashSow outdoors · May 3 – May 17
Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3
GarlicPlant cloves · Oct 1 – Nov 5
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 26) and first fall frost (Oct 15) 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 81077 came on Feb 22 — 20 days earlier than the 1991–2020 average (Mar 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).

Soil in Swink, CO

The soil mapped at the center of ZIP 81077 is Bentfort — silty clay loam, moderately well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH7.8slightly alkaline; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Bentfort silty clay loam, 0 to 2 percent slopes, occasionally flooded.

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 81077; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Swink, CO

Summer high93 °Faverage high, July
Winter low17 °Faverage low, January
Hot days85days a year at 90 °F or more
Freezing nights155nights a year at 32 °F or less
Growing degree days3,656base 50 °F — the season’s usable heat
Longest day14 h 48 mindaylight on June 21
Shortest day9 h 31 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation13 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 46 °F, low 17 °F 46°17° JanFebruary: average high 50 °F, low 20 °F 50°20° FebMarch: average high 61 °F, low 28 °F 61°28° MarApril: average high 68 °F, low 36 °F 68°36° AprMay: average high 77 °F, low 46 °F 77°46° MayJune: average high 88 °F, low 57 °F 88°57° JunJuly: average high 93 °F, low 63 °F 93°63° JulAugust: average high 90 °F, low 61 °F 90°61° AugSeptember: average high 83 °F, low 52 °F 83°52° SepOctober: average high 70 °F, low 37 °F 70°37° OctNovember: average high 57 °F, low 25 °F 57°25° NovDecember: average high 46 °F, low 17 °F 46°17° Dec

Precipitation by month inches

0″1″2″3″January: 0.30 in precipitation 0.3 JanFebruary: 0.34 in precipitation 0.3 FebMarch: 0.82 in precipitation 0.8 MarApril: 1.34 in precipitation 1.3 AprMay: 1.62 in precipitation 1.6 MayJune: 1.67 in precipitation 1.7 JunJuly: 2.44 in precipitation 2.4 JulAugust: 1.78 in precipitation 1.8 AugSeptember: 0.88 in precipitation 0.9 SepOctober: 1.03 in precipitation 1.0 OctNovember: 0.41 in precipitation 0.4 NovDecember: 0.33 in precipitation 0.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: La Junta, CO (4 mi away); precipitation: Rocky Ford 2.9 Ese, CO (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

810676a
Rocky Ford, CO · 6 mi
810306a
Cheraw, CO · 8 mi
810506a
La Junta, CO · 14 mi
810586a
Manzanola, CO · 16 mi
810345b
Crowley, CO · 18 mi
810765b
Sugar City, CO · 22 mi
810626a
Olney Springs, CO · 27 mi
810635b
Ordway, CO · 30 mi

Colorado planting zones →

Questions about 81077

What planting zone is ZIP code 81077?

ZIP code 81077 (Swink, 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 Swink, CO?

The median last spring frost (32 °F) near 81077 is April 26; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, La Junta station.

When is the first frost in Swink, CO?

The median first fall frost near 81077 is October 15, giving a median frost-free growing season of 171 days.

When should I plant tomatoes in 81077?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 81077 get?

About 13 inches of precipitation a year (NOAA 1991–2020 normals, Rocky Ford 2.9 Ese station).

How hot do summers get in Swink, CO?

The average high peaks at 93 °F in July, with about 85 days a year at 90 °F or more.

What kind of soil does 81077 have?

The USDA soil survey maps Bentfort at the center of ZIP 81077: silty clay loam, moderately well drained, pH about 7.8 (slightly alkaline).

Did spring come early in Swink, CO in 2026?

Spring leaf-out near 81077 came on Feb 22 in 2026, 20 days earlier than the 1991–2020 average (Mar 14), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Swink, CO?

Intermediate onions: the longest day near 81077 is 14 h 48 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 81077 change?

Yes. The 2012 USDA map put 81077 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.