At least one official in California has recommended that residents wear masks indoors because of an increase in COVID-19 in recent days.

Wastewater data released by the Centers for Disease Control and Prevention on Sept. 4 show that California is seeing “very high” levels of the virus and that all states on the West Coast are at either “high” or “very high” levels.

The top health official for Yolo County, located outside Sacramento, said in a statement that residents are advised to wear masks indoors. No mandate was issued.

“California is experiencing a summer COVID wave,” Aimee Sisson, the Yolo County health officer, said in the statement. “Based on current wastewater levels of the virus that causes COVID-19, I recommend that everybody in West Sacramento wear a mask when they are around others in indoor public spaces.

“I also recommend that people in the rest of Yolo County wear masks when they are around others indoors if they are 65 or older, have a weakened immune system, have an underlying medical condition that puts them at a greater risk of severe COVID-19, or spend time around people who fall into these categories.”

Sisson’s office also said in a statement issued by the county that “wearing a high-quality mask such as an N95, KN95, or KF94 that fits well continues to provide strong protection” before touting vaccines for the virus.

The San Francisco Department of Public Health told the Los Angeles Times, in an article published on Sept. 3 that suggests multiple California officials have recommended masking, that it is also recommending people “consider wearing a well-fitted mask in crowded indoor spaces, including when traveling, and to stay at home if they feel sick.”

The city health department did not respond to a request for comment.

In Canada, New Brunswick’s Horizon Health Network told The Epoch Times this week that it would mandate masks for certain clinical areas because of a rise in respiratory illnesses such as COVID-19. Several weeks ago, the government of Honduras announced it had reinstated a nationwide mask mandate in health care settings because of a rise in respiratory viruses.

In 2024, multiple California counties implemented mandatory mask requirements in health care settings that lasted from November to the spring of 2025, including counties in the San Francisco Bay Area. Some of the countywide mandates were meant only for employees, but one county required all visitors and patients to wear a mask.

The Epoch Times contacted the California Department of Public Health for comment. An update on the agency’s website posted in late June recommends that certain people wear masks or an N95 respirator variant, particularly if they suspect they were exposed to an infection or “are at a high-risk of becoming severely ill.”

It comes as California, Oregon, Washington state, and Hawaii formed a “West Coast Health Alliance” in response to decisions made by U.S. Secretary of Health Robert F. Kennedy Jr., including his shakeup of the CDC’s advisory panel.