New York City public school kids will return to the classroom in three weeks, but with slim details available about the plan for some 18,000 migrant students and an impending bus strike, parents are starting to panic.

So where is Big Apple Schools Chancellor David Banks ahead of the first day of school on Sept. 7?

Based on multiple sources, NYC’s top educator and his fiancé, Sheena Wright, the city’s first deputy mayor, are currently vacationing in Martha’s Vineyard.

“Everyone needs a break, I get it but … but he is the leader of our school system,” Yiatin Chiu, a parent advocate in Brooklyn, told The Post.

“We are just weeks away from the start of the school year. As the symbolic leader of our school system, I’d like to hear that he’s as concerned as parents about what’s going to happen in our schools.”

The Department of Education boss’ break comes as City Hall sources warned the Big Apple was bracing for a huge, new wave of asylum-seeking students – causing parents to fret over what plans, if any, are in place to help schools cope. 

Chiu, whose daughter attends a south Brooklyn middle school, said parents have so far been met with radio silence about the expected influx of new migrant kids.

“Parents are alarmed,” she said.

“It’s really irresponsible if city agencies are not preparing superintendents or principals. It wouldn’t surprise me if they want to keep parents in the dark.”

She added: “The management of the schools needs to know what to do!”

Craig Slutzkin, a finance worker and member of the Community Education Council District 2, said he, too, hadn’t been told about “specific plans” but was expecting that work was going on behind the scenes.

“I would be hopeful that the DOE is actually making them, especially focusing on appropriate personnel who will be placed at the appropriate schools, for example: bilingual teachers where they are expecting to have a large population of asylum-seeking children,” said Slutzkin, whose son attends PS340 on West 17th Street.

“I’m a little concerned that we haven’t heard a lot from the DOE on this, but this is something they are probably trying to figure out before consulting.”

Another concerned Manhattan parent leader, who didn’t want to be named, fumed that the DOE’s failure to outline the specifics, including if extra Spanish-fluent teachers will be brought into schools in close proximity to migrant shelters, was akin to a “five-alarm fire.”

“I’ve been panicking about that myself, and we need answers with concrete steps and to know who’s going to be held responsible,” he said.

The father said parents have been writing to Banks to get answers, but claims they have “not been addressed and answered yet.”  

“It’s going to be an interesting first few weeks of school for schools that haven’t had to deal with the migrant crisis yet,” the dad warned.

City officials confirmed Wednesday that DOE officials have been on-site at various emergency shelters across the five boroughs to help enroll thousands of migrant children in public schools.

The number of migrant kids enrolled in the city schools topped 18,000 as of July, Fabien Levy, the deputy mayor for communications, said during a Wednesday briefing on the asylum seeker crisis.

Ted Long, a top official at the city’s public hospital system, added that healthcare workers had also vaccinated 30,000 kids at shelters in advance of the new school year.

In addition to the migrant crisis, Banks warned during a parent advisory meeting last week that a potential school-bus-driver strike could also impact up to 150,000 city students as the school year begins amid ongoing negotiations with the Amalgamated Transit Union.

In that instance, the city has detailed contingency plans — including giving students MetroCards and “reimbursement for the use of alternative transportation” that could include “free ride-share.”

‘With so many emergencies happening and school starting in a few weeks, this is the worst time to be vacationing,” a City Hall source said, referring to both the migrant crisis and possible bus driver strike.

Banks, who sources say was poised to skip an in-person appearance at a Panel for Educational Policy meeting Wednesday night amid his vacation, didn’t immediately respond to The Post’s request for comment.

The DOE and City Hall also didn’t respond to The Post’s request for comment.