When to plant in San Diego, CA
USDA Zone 10bSan Diego, California frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
San Diego enjoys a long ~349-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. San Diego's nearest full-normals station sits about 18 km out, so treat these as a close estimate — local microclimate can nudge your first and last frost. In zone 10b, frost is a minor factor for San Diego — most perennials thrive, and annual vegetables can go out early and stay late.
The average last spring frost in San Diego is now 6 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
EL CAJON · 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 San Diego’s own odds, recorded at EL CAJON.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Mar 3 | Feb 6 | Jan 6 | Nov 18 | Dec 6 | Dec 29 |
| 32°F | Feb 7 | Jan 6 | Dec 13 | Dec 1 | Dec 21 | Jan 15 |
| 28°F | Jan 15 | Dec 31 | Dec 8 | Dec 7 | Dec 30 | Jan 14 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in San Diego, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 28 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.
San Diego planting FAQ
When is the last spring frost in San Diego, CA?
Plan for the last spring frost in San Diego around January 6 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in San Diego, CA?
Expect San Diego's first fall frost near December 21 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is San Diego in?
San Diego is in USDA hardiness zone 10b. In zone 10b, winters are mild — many tender perennials overwinter here.
How long is the growing season in San Diego?
San Diego has about 349 frost-free days — a long growing season — between the average last spring frost (January 6) and first fall frost (December 21).
When should I plant tomatoes in San Diego?
For San Diego, sow tomatoes indoors about November 11–November 25 and move the seedlings out around January 13, after the last spring frost.
Never miss a window in San Diego
An email when it’s time to start seeds, transplant, and sow — timed to San Diego’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- La Mesa · 11 km
- Santee · 13 km
- Lemon Grove · 14 km
- El Cajon · 15 km
- Casa de Oro-Mount Helix · 16 km
- Bostonia · 17 km
- La Presa · 17 km
- Spring Valley · 18 km
Frost dates recorded at EL CAJON, 18 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 San Diego, CA — Frost Dates & Zone 10b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00042706. Retrieved from https://blissgarden.com/california/san-diego.