Data report · 2026
Global Sea Temperature Report 2026
Typical sea-surface temperatures for 4,957 beaches in 119 countries and 87 seas, built from long-term climatology. Free to cite and republish with a link.
4,957
Beaches analysed
119
Countries
18.8°C
Global annual mean
76%
Beaches reaching 20°C+
Key findings
- The warmest sea at its peak is the Andaman Sea (30.0°C in Apr).
- The coldest sea at its peak is the Celtic Sea, topping out at only 16.6°C.
- Thailand has the longest swim season: 12 months a year above 20°C.
- The warmest beach in January is Kuta Beach, Indonesia (29.0°C).
Seas ranked by peak temperature
| # | Sea | Peak | Peak month | Coldest | Seasonal swing | Beaches |
|---|---|---|---|---|---|---|
| 1 | Andaman Sea | 30.0°C | Apr | 27.1°C | 2.9°C | 14 |
| 2 | Gulf of Thailand | 30.0°C | Apr | 27.0°C | 3°C | 42 |
| 3 | Andaman Sea | 30.0°C | Apr | 27.2°C | 2.8°C | 40 |
| 4 | Bay of Bengal | 30.0°C | Apr | 27.0°C | 3°C | 5 |
| 5 | Gulf of Mexico | 29.4°C | Jul | 19.3°C | 10.1°C | 136 |
| 6 | Caribbean Sea | 29.0°C | Sep | 26.1°C | 2.9°C | 102 |
| 7 | South China Sea | 29.0°C | May | 26.0°C | 3°C | 16 |
| 8 | Sulu Sea | 29.0°C | May | 26.0°C | 3°C | 9 |
| 9 | Arabian Sea | 29.0°C | May | 25.0°C | 4°C | 8 |
| 10 | Arabian Sea | 29.0°C | May | 25.0°C | 4°C | 17 |
| 11 | Sulu Sea | 29.0°C | May | 26.0°C | 3°C | 24 |
| 12 | South China Sea | 29.0°C | May | 26.0°C | 3°C | 7 |
| 13 | Bali Sea | 29.0°C | Jan | 27.0°C | 2°C | 9 |
| 14 | Sea of Cortez | 29.0°C | Jun | 25.0°C | 4°C | 7 |
| 15 | Bohol Sea | 29.0°C | May | 26.0°C | 3°C | 8 |
| 16 | Philippine Sea | 29.0°C | May | 26.0°C | 3°C | 9 |
| 17 | Caribbean Sea | 28.9°C | Aug | 25.9°C | 3°C | 139 |
| 18 | Coral Sea | 28.0°C | Feb | 22.0°C | 6°C | 32 |
| 19 | Persian Gulf | 28.0°C | Jul | 19.2°C | 8.8°C | 15 |
| 20 | Gulf of Oman | 28.0°C | Jul | 22.8°C | 5.2°C | 5 |
| 21 | Red Sea | 28.0°C | Aug | 19.3°C | 8.7°C | 12 |
| 22 | Lake Michigan | 28.0°C | Jul | 18.0°C | 10°C | 13 |
| 23 | East China Sea | 28.0°C | Jul | 18.8°C | 9.2°C | 8 |
| 24 | Coral Sea | 28.0°C | Feb | 22.0°C | 6°C | 32 |
| 25 | Red Sea | 28.0°C | Jul | 20.0°C | 8°C | 16 |
| 26 | Indian Ocean | 26.9°C | Feb | 23.3°C | 3.6°C | 73 |
| 27 | Mediterranean Sea | 26.5°C | Aug | 15.6°C | 10.9°C | 33 |
| 28 | Aegean Sea | 26.1°C | Aug | 15.1°C | 11°C | 163 |
| 29 | Ligurian Sea | 26.0°C | Aug | 13.0°C | 13°C | 30 |
| 30 | Tyrrhenian Sea | 26.0°C | Aug | 13.0°C | 13°C | 47 |
| 31 | Adriatic Sea | 26.0°C | Aug | 12.2°C | 13.8°C | 224 |
| 32 | Ionian Sea | 26.0°C | Aug | 14.5°C | 11.5°C | 78 |
| 33 | Mediterranean Sea | 25.7°C | Aug | 13.8°C | 11.9°C | 553 |
| 34 | Black Sea | 25.6°C | Aug | 6.2°C | 19.4°C | 61 |
| 35 | Indian Ocean | 25.0°C | Feb | 20.5°C | 4.5°C | 93 |
| 36 | Bay of Biscay | 24.6°C | Aug | 13.3°C | 11.3°C | 81 |
| 37 | Atlantic Ocean | 24.5°C | Aug | 16.0°C | 8.5°C | 224 |
| 38 | Great Lakes | 24.3°C | Aug | 6.8°C | 17.5°C | 16 |
| 39 | Pacific Ocean | 24.0°C | Aug | 18.4°C | 5.6°C | 247 |
| 40 | Sea of Japan | 24.0°C | Jul | 12.0°C | 12°C | 9 |
| 41 | Pacific Ocean | 22.4°C | Aug | 18.4°C | 4°C | 337 |
| 42 | Atlantic Ocean | 22.0°C | Aug | 12.6°C | 9.4°C | 839 |
| 43 | Lake Erie | 22.0°C | Aug | 8.0°C | 14°C | 9 |
| 44 | Lake Ontario | 22.0°C | Aug | 0.0°C | 22°C | 5 |
| 45 | Southern Ocean | 21.9°C | Feb | 15.8°C | 6.1°C | 16 |
| 46 | Tasman Sea | 21.6°C | Feb | 14.9°C | 6.7°C | 88 |
| 47 | Southern Ocean | 21.0°C | Feb | 14.0°C | 7°C | 14 |
| 48 | Tasman Sea | 20.2°C | Feb | 13.4°C | 6.8°C | 136 |
| 49 | Bass Strait | 19.0°C | Jan | 12.0°C | 7°C | 40 |
| 50 | Bay of Fundy | 19.0°C | Aug | 0.0°C | 19°C | 5 |
| 51 | North Sea | 18.7°C | Aug | 5.5°C | 13.2°C | 52 |
| 52 | English Channel | 18.6°C | Aug | 9.1°C | 9.5°C | 160 |
| 53 | Baltic Sea | 18.4°C | Aug | 2.3°C | 16.1°C | 163 |
| 54 | Kattegat | 18.0°C | Aug | 2.5°C | 15.5°C | 20 |
| 55 | Cook Strait | 18.0°C | Jan | 12.0°C | 6°C | 10 |
| 56 | Gulf of St Lawrence | 17.9°C | Aug | 1.8°C | 16.1°C | 30 |
| 57 | North Sea | 17.7°C | Aug | 5.9°C | 11.8°C | 169 |
| 58 | Bristol Channel | 17.0°C | Aug | 8.0°C | 9°C | 11 |
| 59 | North Channel | 17.0°C | Aug | 8.0°C | 9°C | 17 |
| 60 | Norwegian Sea | 17.0°C | Aug | 3.0°C | 14°C | 14 |
| 61 | Lake Huron | 17.0°C | Aug | 3.0°C | 14°C | 11 |
| 62 | Irish Sea | 16.8°C | Aug | 8.2°C | 8.6°C | 55 |
| 63 | Irish Sea | 16.7°C | Aug | 8.3°C | 8.4°C | 9 |
| 64 | Celtic Sea | 16.6°C | Aug | 8.4°C | 8.2°C | 40 |
Monthly average by continent
| Continent | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Europe | 11.8°C | 10.9°C | 11.4°C | 12.9°C | 15.6°C | 19.0°C | 21.4°C | 22.4°C | 20.8°C | 18.0°C | 15.3°C | 13.0°C |
| North America | 17.6°C | 17.5°C | 18.2°C | 19.8°C | 21.8°C | 23.9°C | 25.6°C | 25.9°C | 25.2°C | 23.4°C | 20.9°C | 18.7°C |
| Oceania | 20.8°C | 21.3°C | 20.4°C | 19.2°C | 17.7°C | 16.5°C | 15.6°C | 15.5°C | 16.4°C | 17.7°C | 18.8°C | 20.4°C |
| Asia | 24.6°C | 24.8°C | 25.4°C | 26.4°C | 27.2°C | 27.4°C | 27.5°C | 27.5°C | 27.3°C | 26.9°C | 25.9°C | 25.1°C |
| South America | 20.8°C | 20.8°C | 20.6°C | 20.5°C | 20.5°C | 21.0°C | 21.8°C | 22.1°C | 22.4°C | 21.9°C | 21.3°C | 20.8°C |
| Africa | 22.0°C | 22.0°C | 21.9°C | 21.8°C | 22.1°C | 22.5°C | 23.1°C | 23.2°C | 23.6°C | 23.2°C | 22.7°C | 22.3°C |
Longest swim seasons by country (months ≥ 20°C)
| # | Country | Swim months | Peak | Beaches |
|---|---|---|---|---|
| 1 | Thailand | 12 | 30.0°C | 82 |
| 2 | Vietnam | 12 | 29.4°C | 14 |
| 3 | Malaysia | 12 | 29.4°C | 9 |
| 4 | India | 12 | 29.3°C | 26 |
| 5 | Colombia | 12 | 29.0°C | 8 |
| 6 | Indonesia | 12 | 29.0°C | 76 |
| 7 | Philippines | 12 | 29.0°C | 70 |
| 8 | Bahamas | 12 | 29.0°C | 16 |
| 9 | Jamaica | 12 | 29.0°C | 13 |
| 10 | Dominican Republic | 12 | 29.0°C | 23 |
| 11 | Puerto Rico | 12 | 29.0°C | 18 |
| 12 | US Virgin Islands | 12 | 29.0°C | 11 |
| 13 | Turks and Caicos | 12 | 29.0°C | 8 |
| 14 | Aruba | 12 | 29.0°C | 8 |
| 15 | Belize | 12 | 29.0°C | 6 |
| 16 | Saint Lucia | 12 | 29.0°C | 6 |
| 17 | Bonaire | 12 | 29.0°C | 5 |
| 18 | Curacao | 12 | 29.0°C | 9 |
| 19 | Antigua and Barbuda | 12 | 29.0°C | 11 |
| 20 | Honduras | 12 | 29.0°C | 5 |
| 21 | Cuba | 12 | 29.0°C | 6 |
| 22 | Mexico | 12 | 28.9°C | 208 |
| 23 | Oman | 12 | 28.3°C | 11 |
| 24 | Egypt | 12 | 28.0°C | 26 |
| 25 | Barbados | 12 | 28.0°C | 15 |
Warmest beaches in August
- 1. Clearwater Beach, United States30.0°C
- 2. Caladesi Island, United States30.0°C
- 3. Honeymoon Island, United States30.0°C
- 4. Sand Key, United States30.0°C
- 5. Indian Rocks Beach, United States30.0°C
- 6. Madeira Beach, United States30.0°C
- 7. Treasure Island, United States30.0°C
- 8. St Pete Beach, United States30.0°C
- 9. Pass-a-Grille, United States30.0°C
- 10. Fort De Soto, United States30.0°C
Warmest beaches in January
- 1. Kuta Beach, Indonesia29.0°C
- 2. Canggu Beach, Indonesia29.0°C
- 3. Jimbaran Bay, Indonesia29.0°C
- 4. Kuta Lombok, Indonesia29.0°C
- 5. Balangan Beach, Indonesia29.0°C
- 6. Nyang Nyang Beach, Indonesia29.0°C
- 7. Pandawa Beach, Indonesia29.0°C
- 8. Diamond Beach, Indonesia29.0°C
- 9. Crystal Bay, Indonesia29.0°C
- 10. Atuh Beach, Indonesia29.0°C
Coldest beaches in August
- 1. Tahunanui Beach, New Zealand9.0°C
- 2. Kaiteriteri Beach, New Zealand9.0°C
- 3. Marahau Beach, New Zealand9.0°C
- 4. Totaranui Beach, New Zealand9.0°C
- 5. Anchorage Bay, New Zealand9.0°C
- 6. Awaroa Beach, New Zealand9.0°C
- 7. Wharariki Beach, New Zealand9.0°C
- 8. Sumner Beach, New Zealand9.0°C
- 9. New Brighton Beach, New Zealand9.0°C
- 10. Taylors Mistake, New Zealand9.0°C
Cite or link to this report
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Citation
SwimTemperature (2026). Global Sea Temperature Report 2026. https://swimtemperature.com/global-sea-temperature-reportHTML link
<a href="https://swimtemperature.com/global-sea-temperature-report">Global Sea Temperature Report 2026 by SwimTemperature</a>Methodology
Figures are long-term monthly sea-surface temperature normals for each beach, derived from Open-Meteo marine model climatology and averaged per sea, country and continent (groups with fewer than 5 beaches are excluded). They describe typical conditions, not a specific day. See data sources & accuracy or check today's warmest seas.