Find your next lake beach or swimming spot in the United States

Swimming in US lakes: season, safety and water data

Most inland swimming in the United States happens between Memorial Day and Labor Day, when day-use areas open their gates and lifeguard stands go up. Outside those dates the water is usually still open, but restrooms, fee booths and rescue coverage often are not. Mountain reservoirs such as Lake Tahoe stay cold well into July; shallow southern lakes like Lake Okeechobee warm up months earlier.

Two numbers decide most trips. Water temperature tells you whether the swim is pleasant or a shock, and water level tells you whether the ramp, the beach and the shoreline you remember are still there. A reservoir drawn down 10 feet can leave a boat ramp ending in mud and a swim beach twice as wide as usual. We publish both from public agency feeds, with the reading time and the gauge number on every page.

Water level readings on this site come from the U.S. Geological Survey, from the Texas Water Development Board, from the California Data Exchange Center and from Army Corps of Engineers districts. Weather comes from Open-Meteo. Nothing is estimated: when an agency does not publish a figure for a lake, the page says so instead of guessing.

Before you get in, check the operating agency for advisories. Freshwater lakes are monitored unevenly across states, and blue-green algae blooms are seasonal and local. Swim where other people swim, keep children within arm's reach, and treat unsupervised shorelines as unsupervised, because most lake beaches in this guide have no lifeguard.