https://www.mercurynews.com/2020/06/18/californians-required-to-wear-masks-in-most-public-settings-newsom-says/

Californians will now be required to wear face masks in most public settings — including while using public transportation, waiting in lines and in some workplaces — to prevent the spread of coronavirus, Gov. Gavin Newsom said Thursday.

In new guidance from the California Department of Public Health, the governor said that the order came in response to both a growing body of research showing face masks’ effectiveness and the need for more precautions as the state reopens the economy.