With cases of COVID-19 rising locally and increased circulation of the highly transmissible Delta variant, the counties of San Mateo, Alameda, Contra Costa, Marin, San Francisco, Santa Clara, Sonoma, and the City of Berkeley recommend that everyone, regardless of vaccination status, wear masks indoors in public places to ensure easy verification that all unvaccinated people are masked in those settings and as an extra precautionary measure for all.