After dramatically closing at the start of the pandemic in March, New York City public schools reopened for in-person learning in late September. Now, with coronavirus infection rates rising across the city, public schools are on the cusp of moving to full-remote learning again.

Should the average positivity rate go above 3%, Mayor Bill de Blasio has said that schools would close the following day.

Here is the latest on how the city is preparing for the schools closure.

Why are New York City public schools potentially closing?

In July, when Mayor de Blasio set a 3% seven-day rolling average of positive COVID-19 tests as the trigger for when public schools would close, the virus positivity rate in New York City had stayed steadily between 1% to 2% for nearly two months. At the time, the mayor said the aggressive benchmark would prevent another surge of cases: “We're going to be very cautious to not let there be a resurgence. By setting this 3% goal we're sending a message: health and safety first,” he said on July 31st.

How soon could schools close?

The latest citywide positivity rate stands at 2.8%.

On Friday, de Blasio told WNYC's Brian Lehrer that the positivity rate could go over 3% as soon as this weekend, meaning that schools could close as early as Monday.

He said parents should start making plans immediately for the impending closure. “I think that’s the safe way to think about it, have an alternative plan for beginning as early as Monday,” he said.

Listen to Jessica Gould report on the school shutdown plans on WNYC:

Will all city-run schools be affected?

No. A notable exception will be for community based organizations that provide pre-K and 3K. Those schools will stay open, de Blasio said Friday. In addition, the Learning Bridges childcare program will remain open, with a priority for essential workers, the mayor said.

How does the 3% threshold compare to the state's policy? Does the governor have a say?

This summer, Governor Andrew Cuomo also set a state threshold for closing schools at a much higher benchmark: a 9% positivity rate over a seven-day average.

Cuomo has left the decision to close schools up to the mayor, saying Friday he hopes that New York City will reopen them "as quickly as possible."

What have been the results of the city's mandatory school-based COVID testing?

The data has shown very low rates of positive cases in the school-based testing protocol, with 0.16% positivity, according to the most recent data. Dozens of school buildings are currently temporarily closed as per the Department of Education’s COVID-19 case protocols.

What will happen when school buildings close?

The roughly 280,000 students enrolled in blended learning will be switched to full-time remote learning. Each school principal was told Thursday to prepare to transition their students, teachers and staff. “Out of an abundance of caution, and to keep our school communities safe, I am asking all schools to be prepared for a brief time of fully remote learning, system-wide,” said schools Chancellor Richard Carranza in a letter sent to principals Thursday evening.

Carranza called on the administrators to ensure they have updated contact information for all families, to review attendance policies for remote classes, and to prepare to distribute the additional iPads that will be delivered in the next 4-6 weeks for families who will need devices.

How long will the closure last?

De Blasio did not specify how long the closure will last, although he advised parents Friday to “have a plan for the rest of the month of November—I think that’s the safe way to think about it.”

“My goal here if we do have to shut schools is to do it as for as brief a period as possible and come back up,” he said on the Brian Lehrer show.

The United Federation of Teachers union president Michael Mulgrew said he expects schools to stay shut until there’s a seven-day streak of falling COVID-19 rates.

“We would need to see a downward trend for at least seven days. The last thing we would want to do is reopen for three days and have to shut down again,” Mulgrew said Thursday.

What has been the response to the prospect of schools closing?

Some parents have begun urging the mayor to reconsider the 3% threshold, pointing to the lack of evidence of outbreaks in schools as well as the disruption and educational setback another closure could have on many children.

“My older daughter, every single day that she goes to school is the best day of her life. I mean, she just needs this,” said Daniela Jampel, who has two children in blended learning in Washington Heights and organized a petition calling for schools to stay open. Others have pressed de Blasio to consider closing indoor dining and non-essential businesses before shutting down schools.

But the mayor has held firm, saying that he had committed to what amounted to a "social contract" when he set the threshold.

Back in March, when the coronavirus started spreading in New York City, de Blasio was criticized for being slow to close schools. He has repeatedly said they are essential for the well-being of the low-income families who depend on the food and social services provided by the Department of Education.

Even the mayor has recognized the irony.

"I’m the guy who wanted those schools open and fought to get those schools open," de Blasio said on MSNBC.