The Centers for Disease Control is advising people in Chelan, Douglas and Grant counties to wear a mask while inside in public.

The recommendations are based on CDC data showing a high level of new COVID-19 cases in the three counties.

The data is gathered weekly, with the number of Washington counties in the high level jumping from nine to 16 in the most recent compilation.

The CDC reports a low rate of new cases in Kittitas County, while it classifies Okanogan County in the medium category.

New cases are still at a fraction of the level achieved in the North Central Washington region during the peak of the omicron variant earlier this year.

In late January, new cases in Chelan and Douglas counties stood at 3,151 per 100,000 residents over two weeks vs. 353 per 100,000 over two weeks as of June 30.

A new version of omicron is dominant in the U.S.

The subvariant known as BA.5 accounted for nearly 54% of the country's Covid cases as of Saturday, according to the CDC, while a similar subvariant, BA.4, makes up 17% more.