Nine years ago, when my oldest son was in kindergarten, his 6.5-hour school day included just 15 minutes of outdoor recess. That paltry interval was typical of our Minnesota public-school district. Worse, bad weather periodically meant that kids were kept inside to play, sometimes on screens. By first grade, our five-year-old, who was brimming with energy he should have burned through on the playground, started getting in trouble for wrestling his classmates. His punishment: staying inside during recess.

I still get angry when I think about all this, because it was clear then, as it is now, that time outdoors is good for children’s physical and mental health. In recent years, the evidence has only increased: studies consistently show that getting outside boosts kids’ test scores, reduces stress, and improves behavior and fitness. Teachers, too, are more satisfied with their jobs when they get a break from the classroom, even just an hour a week.

Fortunately, a movement to ensure students receive ample outside time has been ramping up, a rare positive side to the pandemic. Rachel Pringle, director of strategy and operations at the advocacy group Green Schoolyards America, says that as teachers, parents, and administrators scrambled to arrange picnic lunches and outdoor classes as a strategy for reducing transmission of the virus, many noticed that the additional fresh air had other benefits. Through its National COVID-19 Outdoor Learning Initiative, Pringle’s organization has extended its work to help integrate outdoor learning into school curricula.

“The pandemic put a spotlight on this,” Pringle told me. “It helped people who may not have thought about it as an option to see it as one.”

Story time at a Chinese school circa 1965 (Photo: Archive Photos/Getty)

Outdoor learning was gaining momentum even before the pandemic, specifically in preschools and kindergartens, but also in private schools, which have the resources and the flexibility to turn research into action. According to a 2020 report by the North American Association for Environmental Education, the number of so-called forest kindergartens and outdoor preschools in the United States has increased nearly …