NEW YORK — A rising number of children can look forward to excruciatingly boring school breaks this year as budget crises in places such as New York, Washington, D.C., Houston and Detroit rob them of the activities and programs that have long defined summer in the city for urban youngsters.

Swimming pools are being closed. Recreation centers are locking their doors. Library summer reading programs are suffering. Openings for short-term jobs have evaporated.

Port Lau’s vacations of boredom ended the summer he was 14, when a city-funded program got him his first job, doing filing and clerical work at the state Supreme Court in Brooklyn. Now 18, the college freshman credits the experience with landing him a string of jobs and internships — including one for which he’ll be traveling to Germany this summer.

But in New York City, the youth employment program that got him the job is facing a cut of more than $15 million, which means that this year the program is slated to have 10,000 fewer spots for young people from the ages of 14 to 24 — a reduction of nearly one-third.

To Lau, it’s one cutback that just doesn’t make sense.

“We are the students of the future. We’re going to be the ones who make New York prosper,” he said. “So why are they trying to limit us?”

A common theme

The stories are similar elsewhere. In Washington, D.C., a summer camp for children whose families come from Ethiopia is losing its city funding, as are more than half the city-funded summer-camp programs serving low-income communities. In Detroit, the youth summer-jobs program is expected to be down to just 1,200 spots — cut from 7,500 two years ago.

This year and last, declines in revenue and reductions in spending across the country are steeper than at any other point in the last quarter-century, according to a National League of Cities survey.

“It’s not necessarily that youth programs are being singled out, it’s that so many other things have already been cut, and everything needs to be examined at this point,” said Christiana McFarland, research manager for the league. “There’s no more wiggle room in the budget.”

Some city officials are trying to fight back with private partnerships. In New York, companies from American Airlines to the firm that runs the Empire State Building have donated $3 million in cash or jobs to the youth-employment program.

Also on the chopping block in New York City’s proposed budget: four swimming pools, New York Public Library children’s program cuts that would result in 70 percent fewer youngsters being served, more than 6,000 public-school teaching jobs, family literacy programs and outreach for homeless youth.

“This is certainly not going to be the year of the child in New York,” said Manhattan Borough President Scott Stringer, one of a number of local officials who have objected to the cutbacks, saying they will most hurt the city’s middle class and working poor.

Mayor Michael Bloomberg has said the changes in city services are regrettable but necessary because of harsh state and federal funding cuts.