80°F is the sweet spot for pool swimming.

Yes, but it depends on who’s swimming and why. For most adults just hanging out or doing gentle laps, 80°F (about 27°C) feels warm enough that you don’t shiver getting in, but cool enough that you don’t feel like you’re in a bath.

If you’re swimming laps seriously, drop it to 78°F—your body generates heat fast and you’ll overheat in warmer water. For kids, elderly, or just lounging on a float, bump it to 82-84°F. Anything above 86°F starts feeling like soup and you won’t want to move.

Keep in mind: the warmer the water, the more bacteria grow and the more chemicals you need. Also your energy bill goes up. So 80°F is a good compromise for most people.

But your pool heater will remind you that comfort costs money.