New York’s coronavirus infection rates have surged to their highest levels since May, pushing 10 counties – including Brooklyn, Rockland and Orange – above a threshold that the Cuomo administration uses to justify travel restrictions on other states.

For the seven days ending Oct. 7, the statewide average rate of new infections per day was 7.4 per 100,000, up from a low of 3.1 in late August, according to Health Department testing data.

This is an installment in a special series of #NYCoronavirus chronicles by Empire Center analysts, focused on New York’s state and local policy response to the coronavirus pandemic.

In 10 counties, the rates exceeded 10 per 100,000 – one of the standards the state uses to determine which states are subject to a travel advisory. Residents of those states are expected to self-quarantine 14 days after arrival in New York. The 10 counties are:

• Chemung, 50.5 per 100,000
• Broome, 38.2
• Rockland, 35.9
• Steuben, 21.6
• Cortland, 19.5
• Orange, 17.3
• Tioga, 14.2
• Greene, 13.3
• Schuyler, 12.0
• Kings (Brooklyn), 10.3

The list includes the state’s largest county – Brooklyn – as well as downstate suburbs and thinly populated rural areas. Taken together they represent almost one-fifth of the state’s population.

On a regional basis, the Southern Tier had the highest infection rate at 22.5 per 100,000, followed by Mid-Hudson at 11.5 and New York City at 7.1.

Governor Cuomo has attributed the state’s worsening outlook to relatively isolated “clusters” in places where compliance with masking and social distancing has been lax. He responded by imposing tighter restrictions on schools, businesses and houses of worship in three neighborhoods of New York City and parts of Orange, Rockland and Broome counties.

Much of the media attention has focused on outbreaks in ultra-Orthodox Jewish enclaves in New York City and the lower Hudson Valley. Other clusters with hundreds of cases each have been linked to the Lighthouse Baptist Church in Horseheads, a nursing home in Corning, and bars and restaurants in the Binghamton area.

Also ticking upward is the state’s coronavirus death rate. Based on data gathered by The New York Times, the seven-day average on Oct. 7 was 13 deaths per day, the highest level since early August. That rate peaked at almost 1,000 per day in mid-April, but dropped to a low of four per day in late September.