Residents in two-thirds of counties in New York are being recommended to wear masks due to high case-counts of COVID-19, including parts of downstate for the first time this spring, according to new data released Friday from the Centers for Disease Control and Prevention.

As of Friday, 45 counties across the region are now classified by the CDC as having "high" community levels of the coronavirus.

The CDC uses a "high," "medium" and "low" classification, which is determined by the number of new cases in the county per 100,000 people in the past seven days; the number of new hospital admissions with COVID-19 in the past seven days per 100,000 people; and the percentage of staffed inpatient beds in use by patients with COVID-19 within a seven-day average.

With a "high" level, the CDC recommends wearing masks in indoor public areas and on public transportation. There are currently no local mask requirements in these areas, outside of the statewide requirement for them in bus and train stations, prisons, state-regulated care settings and homeless shelters. Recently, Albany County's health department again recommended masks in indoor public places.

Gov. Kathy Hochul, who herself tested positive for the virus on Sunday, said two weeks ago that no return of a statewide mask requirement is being considered at this time.

The number of “high” counties has risen steadily since mid-April, starting with ones in Central New York — the region which was the first in New York to have confirmed cases caused a new BA.2 omicron subvariant known as BA.2.12, state officials said at the time. 

There is now only one county in the state the CDC classifies as “low” — the Bronx borough in New York City. But several counties that were previously classified as "high," including Seneca and St. Lawrence, have now dropped to a "medium" level.

Nationwide, there are 137 counties the CDC said have “high” levels of COVID-19, up from 79 a week ago. The vast majority of "high" counties are in the Northeast.

According to state data released Thursday by Hochul’s office, the state’s seven-day average of COVID-19 cases per 100,000 people stood at 51.03. In recent weeks, New York health officials and those in other states have started using cases per 100,000 residents, and not the more traditional percentage of positive results of those who have been tested, as a more accurate way of measuring infection rates.