There’s no need to sit in Hamptons-bound traffic or catch a train upstate to get in your late-summer dose of outdoor adrenaline.

During August and September, New York City rivers, beaches, and parks are at their peak for surfing and beach volleyball to free canoeing.

Even city streets yield to runners, skaters, and cyclists over three Saturdays in August.

Here are 11 summer-only outdoor activities to take advantage of in our concrete jungle gym right now.