PARIS — Every Parisian should be within a seven-minute walk of a shaded, cooled public space by 2030, the city said on Monday, as it unveiled a plan to turn schoolyards, courtyards and parking lots into “cool islands.”

The plan builds on a pilot that replaced asphalt schoolyards with trees, soil and fountains. Those yards now open to the public on summer weekends. “The difference in temperature is not subtle. It is several degrees,” said Claire Martin, who manages the program.

Paris recorded its hottest summer on record last year, with 19 days above 35 degrees Celsius.