California residents will have to wear face masks in all indoor public settings until January 15, regardless of vaccination status.

The rise of the Omicron variant, which is thought to spread more easily, has been detected across the state. California reported the first domestic case of Omicron on December 1. Since Thanksgiving, the statewide seven-day average case rate increased by 47 percent, and hospitalizations spiked by 14 percent. 

The news comes about six months after the Golden State lifted its statewide mask mandate and capacity restrictions, back when the rate of COVID cases were falling. 

“We know people are tired and hungry for normalcy. Frankly, I am too,” Dr. Mark Ghaly, California Health and Human Services secretary, told media on Monday. “That said, this is a critical time where we have a tool that we know has worked and can work.”

There are certain key exemptions to California’s rule: children younger than two, those with medical conditions or disabilities that prevent wearing a mask, people who are hearing impaired and require the ability to see the mouth for communication, and those who face a risk at work if wearing a mask.

The health department cited a series of surveys in the U.S. suggesting a 10 percent increase in self-reported mask wearing tripled the likelihood of slowing community transmission. The state announced this mandate as a way to protect the health of Californians and keep schools and the economy open. California accounts for around 12 percent of all U.S. students ,but only 1 percent of COVID-19 related school closures, and school outbreaks during the Delta surge in July and August were 3.5 times more likely in areas without school mask requirements.

“We know that there’s going to be people who don’t necessarily agree with this, who are tired, who aren’t going to mask,” Ghaly said. “We hope that those are few and far between, that most people see the purpose of doing this over the next month as something to protect them and their communities during a very tough time.”

Prior to the new rule, major cities Los Angeles and San Francisco implemented vaccine mandates for those wishing to enter indoor spaces, including customers and employees. 

Earlier this week, New York imposed a rule requiring businesses to mandate masks or vaccine verification. The measure went into effect December 13 and will be reevaluated January 15.