CHRISTOPHER WEBER  / Associated Press

The University of California, Los Angeles said Thursday it will reinstate an indoor mask policy as coronavirus cases surge in the nation’s most populous state, which now forecasts hospitalizations will nearly triple in the next month.

UCLA’s 45,000 students and all faculty, staff and visitors will be required to wear masks inside starting Friday following “a consistent rise in COVID-19 cases in Los Angeles County and on our campus,” school officials said in a statement.

Los Angeles County’s public health director, Barbara Ferrer, applauded UCLA’s decision, which she said comes amid a “substantial uptick” in cases across the region.

“We encourage businesses and institutions to go ahead and institute those safety protections that make the most sense, including masking requirements when indoors,” Ferrer said during a weekly briefing.

Statewide, the number of confirmed coronavirus infections is averaging more than 10,000 per day, but that’s considered a significant undercount because so many people are testing at home and not reporting the results. The R-effective rate that measures transmission is now above 1, meaning each COVID-19 case is infecting more than one person, causing the virus to spread rapidly.

California’s hospitalizations are approaching 2,000 after falling below 1,000 at the lowest point last month. State models forecast the number will grow to about 5,200 by late June, the highest since February but a far cry from the more than 15,000 in hospitals at the start of the year.

Vaccinations and immunity from people who have already had the disease are keeping many cases less severe, Ferrer said.

Vaccines “remain our best defense against severe illness,” she said.

California’s surge was most pronounced within the nine-county San Francisco Bay Area, which this week topped 50 new cases per 100,000 residents, up from 18 per 100,000 one month ago.

Alameda, Contra Costa and Santa Clara counties have all seen case numbers triple over the past month, while San Mateo County’s case count has doubled.

“This wave is still going, and I have not seen evidence it has peaked yet,” said Dr. Nicholas Moss, health officer for Alameda County. However, intensive care unit admissions are stable and overall hospitalizations remain lower than during any previous surges, Moss told county supervisors during a briefing Tuesday.

The Bay Area’s Berkeley Unified School District this week reinstated an indoor mask mandate for its campuses during the last few weeks of the academic year, including indoor graduations. Officials were having a hard time finding substitutes for teachers who are out sick with COVID-19, the school district said. The school year ends June 3.