NYCHA developments suffered heat and hot-water outages more than 3,500 times this past winter, leaving 339,000 public-housing residents — or four out of five — in the cold, troubling new statistics show.

The outages struck 259 of the embattled New York City Housing Authority’s 326 developments between Oct. 1, 2018, and May 31, 2019, according to data obtained through a Freedom of Information Law request.

Nearly 400,000 New Yorkers live in NYCHA’s 174,000 apartments and more than 150,000 of those homes — or 87% — lost heat or hot water at some point during the winter season.

“This data again demonstrates NYCHA’s daily struggle to ensure that public-housing residents have access to working heat and hot water,” said Lucy Newman, a lawyer with the Civil Law Reform Unit at The Legal Aid Society, which filed the FOIL request.

“As the landlord, NYCHA has a legal and moral obligation to ensure that these necessary utilities are functioning properly.”

The figures show there were 3,559 outages of heat and hot water at NYCHA developments during the winter: 2,341 outages that nixed hot water and 1,218 instances where the heat stopped working.

More than half of the outages, 1,934, were unplanned, the data shows. Even those that were planned are supposed to occur during warmer months.

NYCHA’s records show the outages were most frequent at the Baruch Houses on the Lower East Side, where heat or hot water went out 186 times for at least some residents during the winter.

“We had heaters we’d be forced to buy,” said 72-year-old resident Tomasita Santapau. “If I would be in the living room, I would leave the stove on in the kitchen.”

Zandalee Gonzalez, a 22-year-old resident, said the situation cost her work and time away from school.

“I’m not going to work without taking a bath. I’m a barback, I have to serve people, I have to be clean and smell good,’’ she said.

“I missed my college speech class because of it,” the young woman added. “We have to do presentations, they ask us to wear suits and ties. I can’t present if I’m not clean.”

At the Justice Sonia Sotomayor Houses in Soundview in The Bronx, the heat and hot water was affected 178 times this past winter.

“Most of the time I slept right there on my couch. I got extra blankets,” said resident Blanche Best, 79. “When I went to the back of the apartment, it was like going into a walk-in freezer!”

NYCHA has until October 2024 to reduce heating outages to just 15 percent of apartments during the winter under the agreement City Hall signed with the federal Department of Housing and Urban Development in January.

The agency is under a partial federal takeover because of city mismanagement, including a lead-paint debacle.

NYCHA’s top brass defended their performance in a statement — by pointing out that the agency suffered a thousand fewer outages this winter than the same period the year before.

Additionally, NYCHA bigs claimed they slashed the average length of the outage by half — though that still amounted to nine hours this past winter.

“We’re proud of that progress and are already working through this summer to build on those improvements for the coming winter,” said NYCHA General Manager Vito Mustaciuolo.

Additional reporting by Khristina Narizhnaya and Georgett Roberts