Is the sea warm enough to swim?
Sea temperature, swimming season and wetsuit thickness for 1,642 coastal cities across 196 countries — from satellite measurements, not guesswork.
What you get on every page
- Swimming season — the months the sea is comfortable, at your choice of threshold.
- Month-by-month temperature from satellite measurements.
- Wetsuit thickness for each month, because "can I swim" and "what do I wear" are the same question with different answers.
Find your city → · Where is the sea warm now? · Wetsuit thickness by city
One threshold is not a preference
Below about 15 °C, cold shock response and swim failure are real physiological risks for anyone not acclimatised — not a question of toughness. Where the sea goes below that, the pages say so plainly.