Garden Climate for San Marcos, CA 92078

Zone 10a · Frost-free in most years · Soil 72.1°F today (measured) · See your place on the 2023 USDA zone map

Public NOAA/USDA data, updated 2026-10-16 19:24 UTC.

USDA Plant Hardiness Zone Map · San Marcos focus

2023 USDA Plant Hardiness Zone Map around ZIP 92078, marker at San Marcos, CA
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USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture. Accessed from https://planthardiness.ars.usda.gov/. Rendered unaltered from the PRISM Group, Oregon State University GIS data (https://prism.oregonstate.edu, accessed 15 Oct 2026) with official zone colors. Roads (TIGER/Line 2023 primary roads), place names (2023 Gazetteer) and state lines (2023 cartographic boundaries 1:500k) are drawn on top. Source: U.S. Census Bureau.

Zone
10a
USDA 2023 · 30 to 35°F
Last frost
None
frost-free ≥9 of 10 yrs
Soil temp Measured
72.1°F
↓ 14.7° in 7 days
Chill hours
—
unavailable
Rain
1.91″
since Oct 1 · normal 0.18″

Frost dates for 92078

Frost-free in most years. No 32F freeze in at least 9 of 10 years at this station (NCEI reports no freeze dates; growing season = 365 days).

NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal freeze probabilities (32F) · CA CARLSBAD PALOMAR AP (USW00003177) 8.8 km away 20 yrs of record · 387 ft lower than this ZIP

Newsletter · 92078

Frost alerts and planting reminders for 92078. Coming soon.

Ad strip · leaderboard 970×90 / 728×90

7-day forecast · High / Low / Rain / Frost / Wind

High wind: 1 day(s) with gusts ≥40 mph. Stake and protect transplants.
Fri 16
91° 72° gust 48 mph 💧2%
High wind
Sat 17
89° 65° gust 33 mph 💧2%
Clear
Sun 18
86° 64° gust 16 mph 💧1%
Clear
Mon 19
82° 62° gust 16 mph 💧11%
Clear
Tue 20
72° 58° gust 25 mph 💧65% · 0.06″
Rain
Wed 21
70° 57° gust 21 mph 💧65% · 0.65″
Rain
Thu 22
68° 56° gust 16 mph 💧33% · 0.12″
Clear

NOAA NWS api.weather.gov (SGX). Frost = low ≤32°F · High wind = gust ≥40 mph · 💧 = chance of precipitation and expected amount (NWS quantitative precipitation forecast; blank when NWS gives none) · Rain = chance ≥50%.

What to grow when · 92078

Calendar: San Diego County, coastal (guide Regions 1-2). Planting months from UC Master Gardeners of San Diego County; Master Gardener Association of San Diego County. Harvest months add typical days-to-harvest. This month also checks live soil temperature and the 7-day frost forecast. The harvest planner uses the same calendar. Rules: methodology.

Affiliate links (disclosed). Placeholders, no partners yet:Frost clothSoil thermometer

Questions about 92078

What USDA hardiness zone is 92078?

ZIP 92078 (San Marcos, CA) is in USDA zone 10a (30 to 35°F average annual extreme minimum), per the 2023 USDA Plant Hardiness Zone Map.

When is the last frost in 92078?

The nearest NOAA normals station (Ca Carlsbad Palomar Ap, 8.8 km) records no 32°F freeze in at least 9 of 10 years (1991–2020).

Nearby ZIP codes

92096 San Marcos 92029 Escondido 92009 Carlsbad 92069 San Marcos 92091 Rancho Santa Fe 92081 Vista

Sources for this page

  • Location: US Census Bureau 2023 Gazetteer, ZCTA internal point
  • Zone: USDA Plant Hardiness Zone Map 2023, ZIP datasets (USDA ARS + PRISM Climate Group, Oregon State University)
  • Frost: NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal freeze probabilities (32F) CA CARLSBAD PALOMAR AP (USW00003177) 8.8 km away 20 yrs of record · 387 ft lower than this ZIP
  • Forecast: NOAA National Weather Service api.weather.gov (7-day forecast + gridpoint wind gusts)
  • Soil: NOAA U.S. Climate Reference Network (USCRN) hourly02, SOIL_TEMP_10
  • Chill: RuntimeError: not enough nearby data: no suitable hourly weather station within 25 km
  • Raw data: /data/zip/92078.json