Where is the sea warmest in the world?
The warmest water in the world month by month, across 1,642 coastal cities — and how many of them are comfortable enough to swim in.
| Month | Warmest city | Sea | Comfortable |
|---|---|---|---|
| January | Morondava | 30.8°C | 917 of 1,642 |
| February | Morondava | 30.6°C | 894 of 1,642 |
| March | Nibong Tebal | 30.5°C | 903 of 1,642 |
| April | Rameswaram | 31.1°C | 940 of 1,642 |
| May | Jizan | 32.1°C | 1,038 of 1,642 |
| June | Şaḩam | 33.1°C | 1,239 of 1,642 |
| July | Khalifah A City | 33.9°C | 1,298 of 1,642 |
| August | Ar Ruways | 34.9°C | 1,352 of 1,642 |
| September | Ar Ruways | 34.3°C | 1,283 of 1,642 |
| October | Jizan | 32.6°C | 1,238 of 1,642 |
| November | Darwin | 31.1°C | 1,120 of 1,642 |
| December | Darwin | 31.0°C | 971 of 1,642 |
"Comfortable" means at least 19.0°C, which is a judgement and not a fact — a Norwegian and a Spaniard genuinely disagree. Every city page shows the season at four thresholds instead of insisting on one. Method and sources