SAN FRANCISCO (KRON) — The Centers for Disease Control and Prevention announced new mask guidelines on Friday — just over a week California dropped its indoor mask mandate.

Most healthy Americans can safely take a break from wearing masks, according to the CDC.

The Bay Area has seen cases go down as it moves past the omicron surge from January.

The CDC broke down Bay Area counties into three categories of COVID-19 transmission in a map updated Thursday: low (green), medium (yellow), and high (orange).

High: Napa and Solano Counties

As of Feb. 18, 76.8 percent of Napa County residents are fully vaccinated, according to the county’s website. That’s 72 percent for Solano residents.

Those numbers are lower than counties like San Francisco and Alameda which are over 80% fully vaccinated.

Counties in the “high” category are the only places where the CDC recommends wearing a mask indoors.

Medium: Santa Clara County

When California lifted its indoor mask mandate on Feb. 16, every Bay Area county except Santa Clara dropped their mandate. Santa Clara County health officials wanted to see a larger decrease in cases and hospitalizations.

That happened, and the county will lift its indoor mask mandate on March 2.

Low: Marin, San Francisco, San Mateo, Alameda, Sonoma, and Contra Costa

These counties are deemed as the safest places to go maskless, according to the CDC.

The counties in the “low” category are where COVID-19 transmission and hospitalizations within the community are low.

The full map of California and the rest of the United States can be viewed here.

How The Data Was Measured

The categories were measured based on two main factors: COVID cases and hospitalizations.

Community transition is considered “low” if there are less than 10% of new COVID cases per 100,000 people in a county. The same applies to if less than 10% of the county’s hospitals are COVID patients.

“Medium:” 10-14.9% for the hospitalization metric and 10-19.9% for new COVID-19 cases.

“High” means over 15% of hospital patients are for COVID and over 20% for new cases.

All the metrics are measured in a 7-day period for every 100,00 people with fewer than 200 cases.

The full breakdown of how the data is measured can be read on CDC’s website.

The Associated Press contributed to this report.