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

Planting zone for 87545 — Los Alamos, NM

ZIP code 87545 (Los Alamos, Los Alamos County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is May 2 and the first fall frost October 12.

Where ZIP 87545 is

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
Coldest night−17.8 to −15 °C
Last frostMay 2
First frostOct 12
2012 zone6b

Was 6b 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 7a means →

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 — within 1 mile, 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 87545

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).

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.

Trees 29

Arizona cypress50 ft · blooms spring · low shade tolerance · to −23 °FArizona madrone30 ft · blooms late spring · high shade tolerance · to −4 °FArizona sycamore80 ft · blooms early spring · high shade tolerance · to −8 °FArizona walnut50 ft · blooms late spring · high shade tolerance · to −33 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblack walnut100 ft · blooms late spring · high shade tolerance · to −28 °F

Shrubs 103

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican tarwort3 ft · blooms late spring · high shade tolerance · to −23 °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 229

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °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 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 163

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °Farctic bluegrass2 ft · high shade tolerance · to −62 °FArizona cottontop4 ft · blooms late summer · high shade tolerance · to −13 °F

Vines 1

western 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 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 36 mindaylight on June 21
Shortest day9 h 43 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

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 40 °F, low 21 °F 40°21° JanFebruary: average high 45 °F, low 24 °F 45°24° FebMarch: average high 53 °F, low 30 °F 53°30° MarApril: average high 61 °F, low 35 °F 61°35° AprMay: average high 70 °F, low 44 °F 70°44° MayJune: average high 81 °F, low 54 °F 81°54° JunJuly: average high 83 °F, low 57 °F 83°57° JulAugust: average high 80 °F, low 55 °F 80°55° AugSeptember: average high 74 °F, low 49 °F 74°49° SepOctober: average high 63 °F, low 38 °F 63°38° OctNovember: average high 50 °F, low 28 °F 50°28° NovDecember: average high 40 °F, low 21 °F 40°21° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.90 in precipitation, 9.9 in snowfall 0.9❄10 JanFebruary: 0.72 in precipitation, 8.8 in snowfall 0.7❄9 FebMarch: 1.04 in precipitation, 5.9 in snowfall 1.0❄6 MarApril: 0.93 in precipitation, 3.3 in snowfall 0.9❄3 AprMay: 1.17 in precipitation, 0.1 in snowfall 1.2 MayJune: 1.17 in precipitation 1.2 JunJuly: 2.94 in precipitation 2.9 JulAugust: 3.20 in precipitation 3.2 AugSeptember: 2.02 in precipitation 2.0 SepOctober: 1.58 in precipitation, 1.7 in snowfall 1.6❄2 OctNovember: 0.95 in precipitation, 4.4 in snowfall 0.9❄4 NovDecember: 0.87 in precipitation, 8 in snowfall 0.9❄8 Dec

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.

Nearby ZIP codes

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

875477b
White Rock, NM · 6 mi
875447a
Los Alamos, NM · 7 mi
875327a
Espanola, NM · 13 mi
875337a
Espanola, NM · 15 mi
870837a
Cochiti Lake, NM · 16 mi
875677a
Santa Cruz, NM · 18 mi
870256b
Jemez Springs, NM · 18 mi
870417a
Pena Blanca, NM · 18 mi

All 2 ZIP codes in Los Alamos → · New Mexico planting zones →

Questions about 87545

What planting zone is ZIP code 87545?

ZIP code 87545 (Los Alamos, NM) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Los Alamos, NM?

The median last spring frost (32 °F) near 87545 is May 2; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Los Alamos station.

When is the first frost in Los Alamos, NM?

The median first fall frost near 87545 is October 12, giving a median frost-free growing season of 162 days.

When should I plant tomatoes in 87545?

Start tomato seeds indoors around Mar 7 – Mar 21 and set transplants outside around May 9 – May 23, one to three weeks after the median last frost.

How much rain and snow does 87545 get?

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

How hot do summers get in Los Alamos, NM?

The average high peaks at 83 °F in July, with about 5 days a year at 90 °F or more.

What kind of soil does 87545 have?

The USDA soil survey maps Vessilla at the center of ZIP 87545: silt loam, well drained, pH about 7.9 (alkaline).

Did spring come early in Los Alamos, NM in 2026?

Spring leaf-out near 87545 came on Mar 10 in 2026, 13 days earlier than the 1991–2020 average (Mar 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Los Alamos, NM?

Intermediate onions: the longest day near 87545 is 14 h 36 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 87545 change?

Yes. The 2012 USDA map put 87545 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.