Garden Climate for Dulzura, CA 91917

Zone 10a · Last frost ~Feb 12 · Soil 64.0°F today (modeled) · See your place on the 2023 USDA zone map

Public NOAA/USDA data, updated 2026-10-16 18:57 UTC.

USDA Plant Hardiness Zone Map · Dulzura focus

2023 USDA Plant Hardiness Zone Map around ZIP 91917, marker at Dulzura, 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
Feb 12
avg last frost (50%)
Soil temp Modeled
64.0°F
↓ 12.6° in 7 days
Chill hours
—
unavailable
Rain
1.31″
since Oct 1 · normal 0.19″

Frost dates for 91917

Last spring frost
Feb 12
50% odds
First fall frost
Dec 24
50% odds
Safer spring date
Mar 20
10% chance of later frost
Growing season
317
days (50%)

Earliest-risk fall date (10%): Dec 2.

NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal freeze probabilities (32F) · CA ALPINE (USC00040136) 25.0 km away 21 yrs of record · 492 ft higher than this ZIP

Newsletter · 91917

Frost alerts and planting reminders for 91917. Coming soon.

Ad strip · leaderboard 970×90 / 728×90

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

High wind: 2 day(s) with gusts ≥40 mph. Stake and protect transplants.
Fri 16
82° 69° gust 60 mph 💧17%
High wind
Sat 17
80° 63° gust 49 mph 💧17%
High wind
Sun 18
80° 62° gust 25 mph 💧0%
Clear
Mon 19
78° 58° gust 18 mph 💧4%
Clear
Tue 20
68° 55° gust 35 mph 💧63% · 0.03″
Rain
Wed 21
63° 53° gust 30 mph 💧67% · 0.44″
Rain
Thu 22
63° 52° gust 22 mph 💧29% · 0.07″
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 · 91917

Calendar: San Diego County, inland valleys (guide Regions 3-4). 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 91917

What USDA hardiness zone is 91917?

ZIP 91917 (Dulzura, 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 91917?

Based on NOAA 1991–2020 normals at Ca Alpine (25.0 km away), the median last 32°F freeze is Feb 12. In 1 of 10 years it is after Mar 20. The median first fall freeze is Dec 24.

Nearby ZIP codes

91935 Jamul 91980 Tecate 91963 Potrero 91978 Spring Valley 92179 San Diego 91915 Chula 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 ALPINE (USC00040136) 25.0 km away 21 yrs of record · 492 ft higher than this ZIP
  • Forecast: NOAA National Weather Service api.weather.gov (7-day forecast + gridpoint wind gusts)
  • Soil: Open-Meteo forecast API soil model (non-commercial terms)
  • Chill: RuntimeError: not enough nearby data: no suitable hourly weather station within 25 km
  • Raw data: /data/zip/91917.json