Seed-start answer
Start tomatoes seeds indoors around Dec 19
In ZIP 92101, start tomatoes seeds indoors around Dec 19, about 42 days before the Jan 30 last-frost estimate.
Source: san-diego-lindbergh frost station, USDA zone 10b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.
This uses ZIP 92101, the San Diego frost station, and the Jan 30 last-frost estimate.
Seed starting schedule
Tomatoes dates for San Diego, CA
| Step | Date | How to use it |
|---|---|---|
| Start Indoors | December 19, 2025 | Start seeds under lights or in a bright indoor seed-starting space. |
| Transplant Outdoors | February 6, 2026 | Move hardened-off seedlings outside after the frost-risk window. |