Question 1

When should I plant watermelon in ZIP 92101?

Accepted Answer

In ZIP 92101, the main watermelon target is around Feb 13, based on the representative San Diego frost station and USDA zone 10b.

Question 2

When should I start watermelon seeds indoors in 92101?

Accepted Answer

Start watermelon seeds indoors in ZIP 92101 around Jan 9, about 21 days before the Jan 30 last-frost estimate.

Question 3

When is the last frost in San Diego?

Accepted Answer

San Diego (ZIP 92101) has an average last spring frost around Jan 30, based on the representative San Diego frost station.

Question 4

When is the first frost in San Diego?

Accepted Answer

San Diego (ZIP 92101) has an average first fall frost around Dec 15, leaving about 319 frost-free days.

Question 5

Is this a guaranteed planting date?

Accepted Answer

No. GrowZone uses frost-date estimates, hardiness zones, and crop timing rules for planning. Local microclimates and current weather can shift the right date.

Step	Date	How to use it
Start Indoors	January 9, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	February 13, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	February 13, 2026	Sow seed outside when the crop and soil can handle the window.

Start watermelon seeds indoors around Jan 9

Watermelon dates for San Diego, CA