Garden Climate for El Cajon, Lakeside & Santee: 92020, 92021, 92040, 92071
Zone 10a · Last frost ~Jan 6 · Soil 66.2°F today (modeled) · See your place on the 2023 USDA zone map
ZIPs in this area
What differs between these ZIPs: elevation, soil temperature. Everything else on this page is the same for all of them. The page below shows 92040 (closest to the area's middle elevation).
| ZIP | Town | Elevation | Zone | Last frost | First frost | Chill hrs last season | Soil now |
|---|---|---|---|---|---|---|---|
| 92020 | El Cajon | 435 ft | 10a | Jan 6 | Dec 21 | 266 | 70.4°F |
| 92021 | El Cajon | 735 ft | 10a | Jan 6 | Dec 21 | 266 | 69.0°F |
| 92040 | Lakeside | 411 ft | 10a | Jan 6 | Dec 21 | 266 | 66.2°F |
| 92071 | Santee | 338 ft | 10a | Jan 6 | Dec 21 | 266 | 70.5°F |
Why grouped: these are urban and suburban lowland ZIPs (under about 1,500 ft and within 40 km of the ocean) whose numbers are close: median last frost dates within about two weeks of each other, last season's chill hours all in the 100-300 range, the same inland setting and the same 820 ft elevation band. Each ZIP still uses its own nearest suitable stations; see the table for exact values.
Public NOAA/USDA data, updated 2026-10-16 19:24 UTC.
USDA Plant Hardiness Zone Map · Lakeside focus
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.
Frost dates for 92040
Earliest-risk fall date (10%): Dec 1.
NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal freeze probabilities (32F) · CA EL CAJON (USC00042706) 6.2 km away 27 yrs of record · 85 ft higher than this ZIP
Newsletter · 92040
Frost alerts and planting reminders for 92040. Coming soon.
7-day forecast · High / Low / Rain / Frost / Wind
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%.
Fruit that fits here
Want to know what fruit and berry varieties will grow well in your area? We rate 250+ peaches, citrus, avocados, figs, berries and more against your chill hours, frost and summer heat.
What to grow when · 92040
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.
Questions about 92040
What USDA hardiness zone is 92040?
ZIP 92040 (Lakeside, 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 92040?
Based on NOAA 1991–2020 normals at Ca El Cajon (6.2 km away), the median last 32°F freeze is Jan 6. In 1 of 10 years it is after Feb 7. The median first fall freeze is Dec 21.
Nearby ZIP codes
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 EL CAJON (USC00042706) 6.2 km away 27 yrs of record · 85 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: Iowa Environmental Mesonet ASOS archive (NWS/FAA METAR routine + special obs; one value per clock hour)
- Raw data: /data/zip/92040.json