Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 30, 2026

Planting zone for Los Alamos, NM

Los Alamos, NM is in USDA zone 7a across its 2 ZIP codes. The median last spring frost is May 2 and the first fall frost October 12.

Los Alamos 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.

Zone7a0 to 5 °F

ZIP codes2

Last frostMay 2

First frostOct 12

Growing season162 days

7a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Los Alamos, NM…

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 Los Alamos, NM

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 2median — 50% chance of a later frost

Safe for tender plantsMay 17only 10% chance of frost after

First fall frostOctober 12median — 10% chance by Oct 1

Growing season162 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 20 and returns around October 23.

From the NOAA station Los Alamos, NM, elevation 7,425 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 Los Alamos

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 21 – Apr 4

SpinachSow outdoors · Mar 21 – Apr 11

Broccoli, cabbageStart indoors · Feb 21 – Mar 7

Broccoli, cabbageTransplant · Apr 11 – Apr 25

Onion setsPlant outdoors · Apr 4 – Apr 18

PotatoesPlant outdoors · Apr 11 – Apr 25

LettuceSow outdoors · Apr 4 – Apr 18

Carrots, beetsSow outdoors · Apr 11 – Apr 25

TomatoesStart indoors · Mar 7 – Mar 21

TomatoesTransplant · May 9 – May 23

Peppers, eggplantStart indoors · Feb 21 – Mar 7

Peppers, eggplantTransplant · May 16 – May 30

BeansSow outdoors · May 9 – May 23

Sweet cornSow outdoors · May 9 – May 23

Cucumbers, squashSow outdoors · May 9 – May 23

Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31

GarlicPlant cloves · Sep 28 – Nov 2

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 2) and first fall frost (Oct 12) 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 87545 came on Mar 10 — 13 days earlier than the 1991–2020 average (Mar 23).

average
Mar 232026
Mar 10

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 7a in New Mexico

532 plants native to the lower 48 states, recorded in New Mexico, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. 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 Los Alamos, NM.

Soil in Los Alamos, NM

The soil mapped at the center of ZIP 87545 is Vessilla — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH7.9alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.4%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Rock outcrop.

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 87545; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Los Alamos, NM

Summer high83 °Faverage high, July

Winter low21 °Faverage low, January

Hot days5days a year at 90 °F or more

Freezing nights150nights a year at 32 °F or less

Growing degree days2,451base 50 °F — the season’s usable heat

Longest day14 h 35 mindaylight on June 21

Shortest day9 h 44 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation17.5 inper year, rain and melted snow

Snowfall42 inper year; 55 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: Los Alamos, NM (within 1 mile); precipitation: Los Alamos, NM (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Los Alamos

New Mexico planting zones →

Questions about Los Alamos

What planting zone is Los Alamos, NM?

Los Alamos, NM is in USDA hardiness zone 7a on the 2023 map (7a: 0 to 5 °F).

When is the last frost in Los Alamos, NM?

The median last spring frost is May 2 and the median first fall frost is October 12 (NOAA 1991–2020 normals, Los Alamos station).

When can I plant a garden in Los Alamos, NM?

Cool-season crops like peas and spinach go in around Mar 21 – Apr 11; tomatoes, peppers, beans and squash after about May 9, once frost risk has passed.

What kind of onions grow in Los Alamos, NM?

Intermediate onions: the longest day is 14 h 35 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Los Alamos, NM get?

About 17.5 inches of precipitation a year and 42 inches of snowfall (NOAA 1991–2020 normals).