The heatwave around the Bay Area has caused massive rolling blackouts by PG&E. Advance warning isn't given by the utility company but there is a place where you can monitor the outages and plan accordingly.
If you fall under "Outage Block 50," consider yourself lucky, you will most likely continue service without interruption. This area includes much of San Francisco and Oakland, and as far north as Santa Rosa. If an Outage Block number and a Sub Outage Block letter appear when you enter your address, you take the number and the letter, put them together, and that's the block number you're looking for on the PG&E schedule.