California is experiencing a late-summer spike in COVID-19 cases, prompting county officials to recommend resuming indoor mask use.
According to the Centers for Disease Control and Prevention (CDC), coronavirus infections are either “growing” or “likely growing” in 30 states, including California.
Wastewater monitoring also shows persistently high viral activity throughout the Golden State.
Dr. Aimee Sisson, Yolo County health officer, confirmed that the state is facing a “summer COVID wave” and advised that everyone aged 2 and older in West Sacramento wear masks in indoor public spaces.
She emphasized that high-quality masks such as N95s, KN95s or KF94s remain important when combined with up-to-date vaccinations to protect against infection.
San Francisco health officials issued similar warnings, urging residents to consider masks in crowded indoor areas and to stay home when feeling unwell.
The city stressed layered precautions, including vaccination and masking, to limit transmission.
Recent data show rising positivity rates across California. For the week ending Aug. 23, 12.07 percent of tests returned positive, roughly double the late-July figure.
County-level trends include Los Angeles at 13.44 percent, Orange County at 18.1 percent and San Francisco at 8.7 percent, according to The Los Angeles Times.
Dr. Elizabeth Hudson, regional chief of