When to plant in Los Alamos, NM
USDA Zone 7bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Los Alamos, New Mexico — all computed from Los Alamos's nearest NOAA weather station.
Zone 7b means many perennials and even some tender shrubs overwinter in Los Alamos, while your frost dates still decide when annuals go out.
Frost probability
LOS ALAMOS · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Los Alamos’s own odds, recorded at LOS ALAMOS.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 31 | May 16 | Apr 30 | Sep 19 | Oct 4 | Oct 17 |
| 32°F | May 17 | May 2 | Apr 19 | Oct 1 | Oct 12 | Oct 25 |
| 28°F | May 4 | Apr 20 | Apr 6 | Oct 9 | Oct 23 | Nov 6 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Los Alamos, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 24 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Los Alamos planting FAQ
When is the last spring frost in Los Alamos, NM?
Los Alamos's average last spring frost falls near May 2 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Los Alamos, NM?
The first fall frost in Los Alamos typically arrives around October 12 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Los Alamos in?
Los Alamos is in USDA hardiness zone 7b. In zone 7b, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Los Alamos?
There are roughly 163 frost-free days in Los Alamos (a moderate growing season), running from the average last frost around May 2 to the first fall frost near October 12.
When should I plant tomatoes in Los Alamos?
In Los Alamos, start tomato seeds indoors around March 7–March 21, then transplant seedlings outdoors around May 9 once the danger of frost has passed.
Never miss a window in Los Alamos
An email when it’s time to start seeds, transplant, and sow — timed to Los Alamos’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Española · 23 km
- Santa Fe · 38 km
- Rio Rancho · 77 km
- North Valley · 86 km
- Albuquerque · 94 km
- Las Vegas · 102 km
- South Valley · 105 km
- Los Lunas · 130 km
Frost dates recorded at LOS ALAMOS, 4 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Los Alamos, NM — Frost Dates & Zone 7b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00295084. Retrieved from https://blissgarden.com/new-mexico/los-alamos.