January | February | March | April | May | June | July | August | September | October | November | December
| 1st | 1.8 | 2.1 | 2.4 | 2.6 | 2.7 | 2.7 | 2.5 | 2.2 | 1.9 | 1.7 | 1.7 | 1.7 | 1.9 | 2.2 | 2.5 | 2.7 | 2.8 | 2.7 | 2.5 | 2.3 | 2.0 | 1.7 | 1.5 | 1.5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2nd | 1.6 | 1.8 | 2.1 | 2.3 | 2.6 | 2.7 | 2.7 | 2.5 | 2.3 | 2.1 | 1.8 | 1.7 | 1.7 | 1.9 | 2.1 | 2.3 | 2.5 | 2.6 | 2.6 | 2.5 | 2.3 | 2.0 | 1.8 | 1.6 |
| 3rd | 1.5 | 1.6 | 1.8 | 2.0 | 2.3 | 2.6 | 2.7 | 2.7 | 2.6 | 2.4 | 2.1 | 1.9 | 1.7 | 1.7 | 1.8 | 2.0 | 2.2 | 2.4 | 2.6 | 2.6 | 2.5 | 2.4 | 2.1 | 1.8 |
| 4th | 1.5 | 1.5 | 1.5 | 1.7 | 2.0 | 2.4 | 2.6 | 2.8 | 2.9 | 2.7 | 2.5 | 2.1 | 1.8 | 1.6 | 1.5 | 1.6 | 1.8 | 2.1 | 2.4 | 2.6 | 2.7 | 2.6 | 2.4 | 2.1 |
| 5th | 1.7 | 1.5 | 1.4 | 1.5 | 1.7 | 2.1 | 2.5 | 2.8 | 3.0 | 3.0 | 2.8 | 2.5 | 2.1 | 1.7 | 1.4 | 1.4 | 1.5 | 1.8 | 2.2 | 2.5 | 2.7 | 2.7 | 2.6 | 2.3 |
| 6th | 2.0 | 1.6 | 1.4 | 1.3 | 1.5 | 1.8 | 2.2 | 2.6 | 2.9 | 3.1 | 3.0 | 2.8 | 2.4 | 1.9 | 1.5 | 1.3 | 1.3 | 1.5 | 1.9 | 2.3 | 2.6 | 2.8 | 2.8 | 2.6 |
| 7th | 2.3 | 1.9 | 1.5 | 1.3 | 1.3 | 1.5 | 1.9 | 2.4 | 2.8 | 3.1 | 3.2 | 3.0 | 2.7 | 2.2 | 1.7 | 1.3 | 1.1 | 1.2 | 1.6 | 2.0 | 2.4 | 2.7 | 2.9 | 2.8 |
| 8th | 2.5 | 2.1 | 1.7 | 1.4 | 1.2 | 1.3 | 1.6 | 2.1 | 2.6 | 3.0 | 3.2 | 3.2 | 2.9 | 2.5 | 1.9 | 1.5 | 1.2 | 1.1 | 1.3 | 1.7 | 2.2 | 2.6 | 2.8 | 2.9 |
| 9th | 2.7 | 2.3 | 1.9 | 1.5 | 1.3 | 1.2 | 1.4 | 1.8 | 2.3 | 2.8 | 3.1 | 3.3 | 3.1 | 2.8 | 2.2 | 1.7 | 1.3 | 1.1 | 1.2 | 1.5 | 1.9 | 2.4 | 2.7 | 2.9 |
| 10th | 2.8 | 2.6 | 2.1 | 1.7 | 1.4 | 1.2 | 1.3 | 1.6 | 2.1 | 2.6 | 3.0 | 3.3 | 3.2 | 3.0 | 2.5 | 2.0 | 1.5 | 1.1 | 1.1 | 1.3 | 1.7 | 2.2 | 2.6 | 2.9 |
| 11th | 2.9 | 2.7 | 2.4 | 2.0 | 1.5 | 1.3 | 1.2 | 1.4 | 1.8 | 2.3 | 2.8 | 3.1 | 3.3 | 3.1 | 2.8 | 2.3 | 1.7 | 1.3 | 1.1 | 1.2 | 1.5 | 1.9 | 2.4 | 2.7 |
| 12th | 2.9 | 2.8 | 2.6 | 2.2 | 1.8 | 1.4 | 1.3 | 1.3 | 1.6 | 2.1 | 2.5 | 3.0 | 3.2 | 3.2 | 3.0 | 2.5 | 2.0 | 1.5 | 1.2 | 1.1 | 1.3 | 1.7 | 2.2 | 2.5 |
| 13th | 2.8 | 2.9 | 2.7 | 2.4 | 2.0 | 1.7 | 1.4 | 1.3 | 1.5 | 1.8 | 2.3 | 2.7 | 3.0 | 3.2 | 3.1 | 2.7 | 2.3 | 1.8 | 1.4 | 1.2 | 1.3 | 1.5 | 1.9 | 2.3 |
| 14th | 2.6 | 2.8 | 2.8 | 2.6 | 2.3 | 1.9 | 1.6 | 1.4 | 1.5 | 1.7 | 2.1 | 2.5 | 2.8 | 3.0 | 3.0 | 2.9 | 2.5 | 2.0 | 1.6 | 1.3 | 1.3 | 1.4 | 1.7 | 2.1 |
| 15th | 2.4 | 2.7 | 2.8 | 2.7 | 2.5 | 2.2 | 1.9 | 1.6 | 1.5 | 1.6 | 1.9 | 2.2 | 2.6 | 2.8 | 2.9 | 2.9 | 2.6 | 2.3 | 1.9 | 1.6 | 1.4 | 1.4 | 1.6 | 1.9 |
| 16th | 2.2 | 2.5 | 2.7 | 2.7 | 2.6 | 2.4 | 2.2 | 1.9 | 1.7 | 1.6 | 1.8 | 2.0 | 2.3 | 2.6 | 2.7 | 2.8 | 2.7 | 2.5 | 2.2 | 1.9 | 1.6 | 1.4 | 1.5 | 1.6 |
| 17th | 1.9 | 2.2 | 2.5 | 2.6 | 2.7 | 2.6 | 2.5 | 2.2 | 1.9 | 1.8 | 1.7 | 1.8 | 2.0 | 2.2 | 2.5 | 2.6 | 2.7 | 2.6 | 2.4 | 2.2 | 1.9 | 1.6 | 1.5 | 1.5 |
| 18th | 1.6 | 1.9 | 2.2 | 2.4 | 2.6 | 2.7 | 2.7 | 2.5 | 2.3 | 2.1 | 1.8 | 1.7 | 1.7 | 1.9 | 2.1 | 2.3 | 2.5 | 2.6 | 2.6 | 2.5 | 2.3 | 2.0 | 1.7 | 1.5 |
| 19th | 1.5 | 1.6 | 1.8 | 2.1 | 2.4 | 2.7 | 2.8 | 2.8 | 2.7 | 2.4 | 2.1 | 1.9 | 1.6 | 1.6 | 1.7 | 1.9 | 2.2 | 2.4 | 2.6 | 2.7 | 2.6 | 2.4 | 2.1 | 1.7 |
| 20th | 1.5 | 1.4 | 1.4 | 1.7 | 2.0 | 2.4 | 2.8 | 3.0 | 3.0 | 2.9 | 2.6 | 2.2 | 1.8 | 1.5 | 1.4 | 1.5 | 1.7 | 2.1 | 2.4 | 2.7 | 2.8 | 2.7 | 2.5 | 2.1 |
| 21st | 1.7 | 1.4 | 1.2 | 1.3 | 1.6 | 2.0 | 2.5 | 2.9 | 3.1 | 3.2 | 3.0 | 2.6 | 2.2 | 1.7 | 1.3 | 1.2 | 1.3 | 1.6 | 2.1 | 2.5 | 2.8 | 2.9 | 2.8 | 2.5 |
| 22nd | 2.1 | 1.6 | 1.2 | 1.1 | 1.2 | 1.5 | 2.1 | 2.6 | 3.1 | 3.3 | 3.3 | 3.1 | 2.6 | 2.1 | 1.5 | 1.1 | 1.0 | 1.1 | 1.6 | 2.1 | 2.6 | 2.9 | 3.0 | 2.9 |
| 23rd | 2.5 | 2.1 | 1.5 | 1.1 | 1.0 | 1.1 | 1.5 | 2.1 | 2.8 | 3.2 | 3.5 | 3.4 | 3.1 | 2.5 | 1.9 | 1.3 | 0.9 | 0.8 | 1.1 | 1.6 | 2.2 | 2.7 | 3.0 | 3.1 |
| 24th | 2.9 | 2.5 | 2.0 | 1.4 | 1.0 | 0.9 | 1.1 | 1.6 | 2.3 | 2.9 | 3.4 | 3.6 | 3.4 | 3.0 | 2.4 | 1.7 | 1.1 | 0.7 | 0.8 | 1.1 | 1.7 | 2.3 | 2.8 | 3.1 |
| 25th | 3.1 | 2.9 | 2.4 | 1.8 | 1.3 | 1.0 | 0.9 | 1.2 | 1.8 | 2.4 | 3.1 | 3.5 | 3.6 | 3.4 | 2.9 | 2.2 | 1.5 | 0.9 | 0.7 | 0.8 | 1.2 | 1.8 | 2.4 | 2.9 |
| 26th | 3.1 | 3.1 | 2.8 | 2.3 | 1.7 | 1.2 | 1.0 | 1.0 | 1.4 | 1.9 | 2.6 | 3.2 | 3.5 | 3.5 | 3.2 | 2.7 | 2.0 | 1.3 | 0.9 | 0.7 | 0.9 | 1.4 | 2.0 | 2.6 |
| 27th | 3.0 | 3.1 | 3.0 | 2.7 | 2.2 | 1.6 | 1.2 | 1.0 | 1.2 | 1.5 | 2.1 | 2.7 | 3.2 | 3.4 | 3.3 | 3.0 | 2.5 | 1.8 | 1.2 | 0.9 | 0.9 | 1.1 | 1.6 | 2.2 |
| 28th | 2.6 | 2.9 | 3.0 | 2.9 | 2.5 | 2.1 | 1.6 | 1.3 | 1.2 | 1.4 | 1.8 | 2.3 | 2.8 | 3.1 | 3.2 | 3.1 | 2.7 | 2.2 | 1.7 | 1.2 | 1.0 | 1.1 | 1.4 | 1.8 |
| 29th | 2.3 | 2.7 | 2.9 | 2.9 | 2.7 | 2.4 | 2.0 | 1.6 | 1.4 | 1.4 | 1.6 | 1.9 | 2.4 | 2.7 | 3.0 | 3.0 | 2.8 | 2.5 | 2.1 | 1.6 | 1.3 | 1.2 | 1.3 | 1.6 |
| 30th | 2.0 | 2.3 | 2.6 | 2.8 | 2.8 | 2.6 | 2.3 | 2.0 | 1.7 | 1.5 | 1.5 | 1.7 | 2.0 | 2.4 | 2.6 | 2.8 | 2.7 | 2.6 | 2.3 | 2.0 | 1.7 | 1.4 | 1.4 | 1.5 |
Source: Hydrographic Department, Royal Thai Navy