The region is about to experience its first real hot spell of the season, and that means pool time for many Philadelphians. This year, however, swimmers can expect to wait in line at some city pools. The reason: not enough lifeguards.

As it has for the last few summers, the city’s Parks and Recreation Department has struggled to hire enough lifeguards. As of Tuesday, the city had 350 lifeguard spots filled out of the 400 needed to be fully staffed.

On Tuesday, swimmers impatiently waited for the gates to open to Kelly Pool in Fairmount Park.

“This is longer than usual,” Jean Voightsberger said as she noted that it was 12:10 p.m., and while the pool was supposed to open at noon this week, she recalled last year’s opening time was 11 a.m.This week, the pool is operating on a reduced schedule.

Finally, at 12:15, the lifeguards let her in, and a few others who were also lined up. At least she got in. On Saturday, dozens of children and adults had to wait because the pool wasn’t fully staffed and couldn’t accommodate everyone.

Parks and Recreation Commissioner Kathryn Ott Lovell said the lifeguard shortage follows a national trend. High school and college students are no longer interested in working as lifeguards and would rather opt for summer internships or participate in competitive sports leagues.

One issue that keeps coming up among city youth is that many can’t swim.

“We will train them” to be lifeguards, Lovell said. “But they have to come with a base level of how to swim.”

The recreation department offers free swimming lessons, and this year it doubled to 100 the number of youths signed up for the “Swim for Life” program, an intensive swim camp. Lovell is hoping these programs will pay dividends later.

“We need to have a pipeline of kids who can become lifeguards so we don’t have this problem each year,” she said.

Lovell said that recruitment for lifeguards usually starts in January, but that students aren’t thinking about summer jobs then. Once school lets out in early June, it’s usually too late for them to try out and complete the city hiring process, which takes four to six weeks.

The city got rid of its residency requirement for lifeguard jobs several years ago and has increased the pay. For a first-time lifeguard, pay is $13.65 an hour and can go up to $15 an hour after the first year. Lovell said that’s higher than the national average.

Even with those incentives, city and suburban kids are not racing to become lifeguards. Instead, the city has been hiring retired teachers and other retirees to take what used to be jobs almost exclusively held by teens.

Thurston Moon, a math and science teacher with the Philadelphia School District, has been a summer lifeguard for several years. As he opened up Kelly Pool Tuesday, he pointed out that the pool draws not only from local neighborhoods but also citywide, since it is one of the few free Olympic-size pools in the area.

He said the lifeguards rotate people out of the pool every hour because of the demand. There has to be a lifeguard for every 20 swimmers in deep-end pools, and one lifeguard for every 30 swimmers in the 4-foot-deep pools.

The shortage doesn’t mean more people per lifeguard. Instead, it affects "the number of people that can come into the area,” he said.

In part because of the staffing shortage, the public pools have been opening on a rolling schedule and with reduced hours. Instead of the usual 11 a.m. to 7 p.m., pools have been open from noon to 5 p.m. during the first two weeks of the season.

Lovell said she hopes to have all pools operating from 11 a.m. to 7 p.m. by next week.

For those interested in becoming a lifeguard next summer, the city will start certification training in August. The training course fee is $110 if the person commits to working for the city pools, or $175 if the person wants to work elsewhere.

Lovell said that city residents who can’t pay the fee up front can repay the city through paycheck deductions once they start working.

“It’s a great job,” she said. “It would be nice if we didn’t have this crunch every year.”