CDC recommends masks again in New York City, Los Angeles and other communities as COVID cases climb

A growing number of communities are now seeing COVID-19 cases and hospitalizations at levels high enough to warrant indoor masking and other measures to curb the virus, the Centers for Disease Control and Prevention warned Thursday. A number of major cities are now mulling a return to masking measures.

According to the agency's weekly update, 13.7% of Americans now live in communities now rated at "high" COVID-19 Community Levels, up from 4.9% of the population last week. An additional 38.1% of Americans are in "medium" areas and 48.2% are in "low" areas. 

More than ten large counties with more than a million residents are now at this "high" tier: