Through Christmas week and possibly longer, residents in California counties in the state's "Purple" tier for reopening must now stop gathering with anyone outside their household after 10 p.m., and outdoor restaurants will all need to shut down at that time — though takeout and delivery can still go on past 10 p.m.

Governor Gavin Newsom announced the curfew Thursday after hinting on Monday that he was considering such a move. Similar curfews have already been put in place in New York City and Los Angeles, as well as in the states of Massachusetts and Virginia. This curfew prohibits "all activities conducted outside the residence, lodging, or temporary accommodation."

San Francisco, for now, will not be impacted by the curfew unless the city's COVID metrics worsen. As of this week, San Francisco moved from the least restrictive "Yellow" tier to the second worst or "Red" tier.

Newsom referred to the order in a tweet as a "limited stay-at-home order."

As the Examiner reports, the curfews take effect on Saturday and extend for one month, until December 21 — though this order may be extended.

"The virus is spreading at a pace we haven’t seen since the start of this pandemic and the next several days and weeks will be critical to stop the surge. We are sounding the alarm," Newsom said in a statement. "It is crucial that we act to decrease transmission and slow hospitalizations before the death count surges. We’ve done it before and we must do it again."

Experts are far from being all on the same page about whether curfews are effective at stemming the spread of a virus like this. As Slate reports, epidemiologist point to unwanted side effects of curfews — for instance, they could condense peoples' restaurant visits into a shorter period of time and therefore cause there to be more crowding in some places.

"Viruses are not vampires," says Angela Rasmussen, a virologist with Georgetown’s Center for Global Health Science and Security.

And, as Eater noted yesterday, Laurie Thomas of the Golden Gate Restaurant Association (GGRA) suggested that a curfew would only further cut into the revenue of the already struggling hospitality industry, and may have the "unintended consequence" of pushing more households to intermingle indoors at home.

And while San Francisco isn't immediately effected, a move to the "Purple" tier is always possible. Meanwhile, most outdoor bars and restaurants around the city seem to be closing by 10 p.m. or earlier anyway.

The curfew will immediately effect all the Bay Area counties now in the "Purple" tier: Alameda, Contra Costa, Solano, Santa Clara, Napa, and Sonoma counties.

Previously: San Francisco Reverts To 'Red' Tier; Five Bay Area Counties Slide Back to 'Purple' As COVID Cases Proliferate

Photo: Drew Beamer