The restrictions, which also cover New Jersey and Connecticut, will be based on specific health metrics related to the virus, Mr. Cuomo said.
Mr. Cuomo said the quarantine would apply to states where either 10 percent of the total population tested positive, or where there were 10 infections per every 100,000 people on 7-day rolling average. Included immediately, he said: Alabama, Arkansas, Arizona, Florida, North Carolina, South Carolina, Utah, Texas and Washington State.
“Any state that has an infection rate above that will be subject to the quarantine,” he said.
The move punctuated a stark shift in the course of the nation’s coronavirus outbreak; for months, the state, particularly New York City, had been a global center of the pandemic. Hospitals filled to near capacity. Hundreds died each day, reaching a peak in mid-April.
“We did a full 180 degrees,” Mr. Cuomo said. “We went from the highest transmission rate to some of the lowest rates in the country.”
Many New Yorkers with the means to do so fled, often to out-of-state locales. By late March, Florida began requiring travelers from the New York area to quarantine. Other states sought to restrict visitors. Researchers later found that by March, New York City had been seeding outbreaks around the country.
Now, the virus appears to be spreading more rapidly outside of New York than inside of the state. New infections are surging in Arizona and Texas. Nearly 20,000 people tested positive for the virus in Florida over the last five days ending Tuesday; in New York, where far more people are being tested daily, roughly 3,200 did during that period.