Not everywhere in California.
Morro Valley (along State Highway 41 near the coast, and near to Morro Bay) has the Northernmost orchards of any size ---that I know of.
There could more, possibly some avocados as far North as Carmel Valley, a little around Salinas possibly(?) on the seaward lands, and maybe in a few micro-climate pockets here and there North to Sonoma County (at best) but past Carmel Valley would be increasingly dicey, wherever the trees could be subject to frost. Morro Valley (further south than those places just listed) gets periodic frosts. I have acquaintances there who own avocado orchards.
Down South (California) the best orchards were near to and inland of San Diego. Ventura-Santa Barbara coast had (likely still has) more than a few sizable orchards...and I think the valley that runs from Oxnard over to I-5 has avocados.
Central Valley? Forget it. There may not be frost every year, but often enough that one would have to be cutting back to stumps far too often. Most of the San Joaquin-- similar problem, though not as acute.
Texas has too much frost. What's left? Florida? I don't think they grow much of the Hass variety (I could be wrong, and who knows? maybe that could change? -- but I seem to recall encountering online discussion of this issue among Florida growers with the consensus seeming to be that those who were already growing the Florida varietals would continue with what was working in their own locale, already -- meaning-- nobody much was moving towards growing Hass and varieties more similar to Hass than to the Florida types).
I believe pre NAFTA Mexican avocados were not allowed imported. Or it was a tight quota. I don’t recall exactly but it was a political issue. CA avocado growers had a lot of power.