when to start in coastal so cal?

[paradajky]

I'm in coastal southern california, zone 10a, less than 1 mile from the ocean. 2020 I started seeds in six-pack cells indoor early March, with an upotting in April and final container planting in mid May. Had my first fruits mid to late July. We had fairly wet weather through May here (lots of rain), and the warmer weather hadn't begun until late July early August.

2021 I tried starting indoors in February with a 72 cell tray, with uppoting in March, and beautiful stocky green transplants ready to go into ground in April. However, combination of disease and cooler, overcast weather in the low 60s kept us from having much of a harvest unfortunately - May Gray, June Gloom, and July with Minimal Sky were pretty heavy this year.

Given this data, should I try as early as January, or wait until later? The plants stay indoors until the first uppotting. I don't recall temps here ever getting to "frost", but we've had one or two nights in the high 30s, typically late February and early March. I do not have space to actually grow tomatoes inside, I like to harden them off during the uppotting.

Plants chosen for next season will be a mix of some earlies, and more disease resistant varieties. I plan to start "from scratch" instead of reusing soils, because 2021 reused soil from 2020 and for some reason I think it may have been contaminated and was the reason why everything was so bad.

Thanks for your time!