Sonoma and Contra Costa Counties have moved to the state's red tier for reopening.
Sonoma County made the move at 12 a.m. Sunday. Supervisor David Rabbitt broke the news Friday on a conference call.
Contra Costa County officials said Friday they'd also move into the red tier on Sunday, but didn't specify a time.
As of Friday, both were the only Bay Area counties remaining in the restrictive purple tier.
"It is encouraging to see our data moving in the right direction, and it's a testament to the hard work Contra Costa residents have put in to slow the spread of COVID-19," said Dr. Chris Farnitano, Contra Costa County's health officer. "But it is important that we make healthy choices to keep up our momentum. This pandemic is not over yet."
Contra Costa County Supervisor John Gioia echoed the sentiment, telling KCBS Radio that residents should continue to take precautions such as practicing social distancing and wearing a mask.
"We still have to be aware that there are variants of this virus out there that could cause another surge," he said.
The move means more businesses in Sonoma and Contra Costa Counties are eligible to reopen, include indoor dining, gyms, movie theaters, shopping centers and museums, with specific COVID-19 modifications like capacity limits. Capacity at businesses that have already been open in the purple tier will also be expanded.
Gioia said while going into red does allow most schools to reopen according to state guidelines, it really is up to the individual school districts and teachers unions.
Monterey County will reportedly move into the red tier next week.
Earlier this week, Alameda, Solano and Santa Cruz Counties jumped to the red tier.