The Thailand resorts with the warmest sea water temperature in September are Hat Yai, Narathiwat and Ko Li Pe.
Below you can see a list of all popular Thailand resorts and information about sea water temperature in September for the last two years.
| Resort Name | September 2025 | September 2024 | September 2023 |
|---|---|---|---|
| Hat Yai | 90.0°F | 89.8°F | 89.8°F |
| Narathiwat | 89.9°F | 89.7°F | 89.6°F |
| Ko Li Pe | 89.8°F | 89.6°F | 89.7°F |
| Pattani | 89.5°F | 89.6°F | 89.6°F |
| Cha-am | 89.1°F | 90.0°F | 89.7°F |
| Hua Hin | 89.1°F | 90.0°F | 89.3°F |
| Lamai Beach | 89.0°F | 89.8°F | 89.0°F |
| Taling Ngam Beach | 88.9°F | 89.5°F | 89.0°F |
| Chaweng Beach | 88.9°F | 89.7°F | 88.9°F |
| Bangkok | 88.8°F | 89.7°F | 89.4°F |
| Samui | 88.8°F | 89.6°F | 88.9°F |
| Koh Lan | 88.8°F | 90.0°F | 89.7°F |
| Koh Lanta | 88.8°F | 88.5°F | 89.0°F |
| Choeng Mon Beach | 88.7°F | 89.6°F | 88.8°F |
| Bo Phut Beach | 88.7°F | 89.5°F | 88.8°F |
| Mae Nam Beach | 88.7°F | 89.5°F | 88.8°F |
| Krabi | 88.6°F | 89.0°F | 89.0°F |
| Pattaya | 88.6°F | 89.7°F | 89.4°F |
| Phi Phi | 88.6°F | 88.9°F | 89.1°F |
| Ko Phangan | 88.6°F | 89.4°F | 88.6°F |
| Phangan | 88.6°F | 89.3°F | 88.7°F |
| Jomtien | 88.6°F | 89.7°F | 89.4°F |
| Tao | 88.5°F | 89.4°F | 88.4°F |
| Surat Thani | 88.5°F | 88.5°F | 88.4°F |
| Rayong | 88.4°F | 89.4°F | 88.6°F |
| Koh Chang | 88.2°F | 88.9°F | 88.7°F |
| Samet | 88.2°F | 89.2°F | 88.4°F |
| Ko Wai | 88.1°F | 88.9°F | 88.8°F |
| Ko Mak | 88.1°F | 89.0°F | 88.6°F |
| Cape Panwa | 88.1°F | 88.6°F | 88.7°F |
| Koh Kood | 88.0°F | 89.0°F | 88.5°F |
| Trat | 88.0°F | 88.3°F | 88.6°F |
| Prachuap Khiri Khan | 87.9°F | 89.2°F | 88.3°F |
| Nai Harn Beach | 87.8°F | 88.4°F | 88.6°F |
| Rawai Beach | 87.8°F | 88.4°F | 88.6°F |
| Phuket | 87.8°F | 88.5°F | 88.6°F |
| Mai Khao Beach | 87.8°F | 88.2°F | 88.5°F |
| Nai Yang Beach | 87.8°F | 88.3°F | 88.6°F |
| Karon Beach | 87.7°F | 88.4°F | 88.6°F |
| Kata Beach | 87.7°F | 88.4°F | 88.6°F |
| Surin Beach | 87.7°F | 88.4°F | 88.6°F |
| Kamala Beach | 87.7°F | 88.4°F | 88.6°F |
| Bang Tao Beach | 87.7°F | 88.4°F | 88.6°F |
| Kalim Beach | 87.7°F | 88.4°F | 88.6°F |
| Patong Beach | 87.7°F | 88.4°F | 88.6°F |
| Chumphon | 87.7°F | 88.7°F | 88.2°F |
| Khao Lak | 87.5°F | 87.6°F | 87.9°F |
| Similan | 87.0°F | 87.8°F | 87.8°F |
Please see following sea water temperature averages charts for the warmest Thailand resorts in September.
You can also get the same information for the every other month of the year when the average sea water temperature is greater then 70°F.
Thailand Resorts:
NAME
F°
| Bang Tao Beach |  |
+84 |
| Bangkok |  |
+82 |
| Karon Beach | |
+84 |
| Kata Beach | |
+84 |
| Khao Lak | |
+80 |
| Ko Li Pe | |
+86 |
| Koh Chang |  |
+84 |
| Krabi | |
+82 |
| Patong Beach | |
+84 |
| Pattaya |  |
+84 |
| Phi Phi | |
+84 |
| Phuket | |
+84 |
| Samet | |
+86 |
| Samui | |
+86 |
| Similan | |
+80 |
