Does swimming break my fast?

Water on the body is fine

A fast is broken by things that enter the stomach, not by water on your skin. The Prophet ﷺ was seen pouring water over his head while fasting because of thirst or heat (Sunan Abi Dawud 2365). So a cool shower, a bath or a swim on a hot Ramadan afternoon is allowed. Even ghusl (the full bath) during the day is fine.

The real risk: swallowing water

The Prophet ﷺ told a companion to rinse his nose well in wudu, except when fasting (Sunan Abi Dawud 142). The lesson: water going deep into the nose or mouth can reach the throat, so a fasting person should be careful.

• If you swallow water by accident, most scholars say the fast is still valid, like eating by mistake. The Hanafi and Maliki schools are stricter and say it should be made up, especially if you were careless.
• If you drink pool water on purpose, the fast is broken.
• Diving and deep underwater swimming make accidental swallowing much more likely. Some scholars call it disliked (makruh) while fasting for that reason.

Tips for a fasting swim

• Swim strokes that keep your face above water, like breaststroke with your head up.
• Use a nose clip and keep your mouth closed when you go under.
• Choose a short, easy swim. Long training sessions can dehydrate you, and you can't drink until iftar.
• Swim close to iftar, so you can rehydrate soon after.

For harder training in Ramadan, see Can I exercise while fasting in Ramadan?

Other things to keep in mind

Fasting doesn't change the usual rules about modest swimwear and mixed pools. If you're wondering about those, see Can I still go swimming at a public pool as a Muslim?

Chlorine smell, sunscreen and a bit of water on your lips don't break the fast. The same logic applies to other things on the skin. See Can I wear deodorant while fasting?