If you fill it, they will swim

The hot sun blazes through these June weeks, but don’t even think about swimming in one of New York City’s refreshing, free outdoor public swimming pools. The Parks Department’s 13 Olympicsize wonders and dozens of humbler cooling spots remain chalk dry and locked through the start of summer, opening only on the scorchingly late date of June 29.

They will stay barren even as city officials on Wednesday will announce $106 million in measures to counter the health effects of extreme heat.

Yet even while beaches get lifeguards starting Memorial Day weekend, and parks’ kiddie sprinklers activate when the thermometer goes above 80 degrees, for years pools have opened only after public schools close.

Times, and temperatures, change. Since the city pools opened (in late May) in the 1930s, average June highs have crept up. Recognizing a need, the mayor and City Council have lately extended the end of pool and beach season for an additional six days after its traditional Labor Day closure — costing an additional $1.7 million.

If anything, the case to be made to open at least a few outdoor pools a week or two earlier in June is even stronger.

Money aside, the Parks Department’s perennial challenge is finding enough lifeguards, since many are students on summer break. By mid June, many more college students are available than remain after Labor Day. Hire them.

And mid-June temperatures are a tad higher than mid-September’s, closer to the 80-degreeplus highs that motivate hordes of swimmers to wade in. (No diving!)

This year and its city budget are a lost cause, but on the next lap, June outdoor pools should float high on the city’s priorities.