GrowZone

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

StepDateHow to use it
Start IndoorsDecember 19, 2025Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsFebruary 6, 2026Move hardened-off seedlings outside after the frost-risk window.