It’s that time of year again: back to school. But this year kids are walking back into their classrooms in the middle of a big statewide COVID surge.

The weekly update published Friday by the state health department shows the COVID positivity rate continuing on its steady upward trajectory, reaching 14.7% as of August 12.

The percent of COVID tests that come back positive, known as the positivity rate, is one of the only timely metrics left to track the spread of the virus. California’s rate has yet to show signs of slowing, since it first starting growing in May. The positivity rate is now the highest it’s ever been in August, and approaching the all-time summer high of 16% in July 2022.

Last year’s summer COVID wave peaked in early September, at just over 13%, and the previous year’s summer surge peaked at just over 16%, in mid-July. The all-time high positivity rate was in early January 2022, when it reached over 22%, during the first big Omicron surge.