For children who have fallen far behind academically, it is not yet clear what summer school will look like, since the Department of Education is currently determining how grading and promotion will be handled during remote learning.

Though education officials said the city will offer some virtual learning options through the summer, teachers are still scheduled to begin their summer break at the end of June. Top officials at the United Federation of Teachers indicated that the powerful union would push back vigorously against any attempt to continue the school year online through the summer.

Mr. de Blasio has said the city cannot plan to reopen any schools earlier than September, spelling more uncertainty for children with advanced special needs who typically attend school year-round. And it is unknown when public libraries, where students can study for the SATs and catch up on summer reading assignments, will reopen.

“The things that we would normally plan for the summer we cannot guarantee. We only at this point, I think, can truly plan on the reopening of schools in the beginning of September,” the mayor said last week. “That’s where our energy is going, actually start the schools up right.”

Mr. de Blasio said Wednesday that his administration was working on a “summer plan” to try to keep New Yorkers, including students, occupied in the coming months.

Mr. de Blasio has said the enormous reductions to summer programs were not only necessary for safety but were also part of a painful yet necessary slew of budget cuts aimed at keeping the city afloat as it beats back the virus. The slashing of nearly all summer programs will save the city about $185 million, and closing pools and cutting some funding for parks will save about $17 million.

“We know many of the restrictions put in place to protect the health and safety of New Yorkers are causing unique disruptions in the lives of our kids, especially those in low income communities,” said Jane Meyer, a spokeswoman for Mr. de Blasio.