During months when large waves are predicted, you may be more comfortable flying.
| Andaman Sea - Expected Weather Conditions | ||
| Months | Underwater | Surface |
| Jan-Mar | Excellent | Calm |
| Apr | Good/Excellent | Calm/choppy |
| May-Oct | Poor/Good | Choppy/rough |
| Nov-Dec | Good | Choppy |
| Comment: recent years have seen east winds strengthen and may prevent smaller boats from reaching distant sites | ||
| Koh Phi Phi - Expected Weather Conditions | ||
| Months | Underwater | Surface |
| Jan-Apr | Excellent | Calm |
| May-Jul | Good | Choppy |
| Aug | Fair | Choppy |
| Sep | Fair | Choppy |
| Oct | Fair | Choppy |
| Nov-Dec | Excellent | Calm |
| Comment: Protected because of location | ||
| Koh Lanta Area - Expected Weather Conditions | ||
| Months | Underwater | Surface |
| Jan-Apr | Excellent | Calm |
| May-Jun | Fair | Choppy |
| Jul-Aug | Fair/Poor | Choppy/Large waves |
| Sep-Oct | Poor | Large Waves |
| Nov | Good | Choppy |
| Dec | Excellent | Calm |
| Butang Group/Koh Tarutao - Expected Weather Conditions | ||
| Months | Underwater | Surface |
| Jan-Feb | Good | Choppy |
| Mar | Fair | Choppy |
| Apr | Fair | Calm |
| May | Good | Calm |
| Jun-Aug | Excellent | Choppy |
| Sep-Oct | Excellent | Large waves |
| Nov-Dec | Excellent | Choppy |
| Comment: winds from the west - clean clear water from the Indian Ocean depths | ||
| West Gulf of Thailand - Expected Weather Conditions | ||
| Months | Underwater | Surface |
| Jan-Feb | Fair/Good | Choppy |
| Mar | Excellent | Calm |
| Apr-Jun | Fair/Good | Choppy |
| Jul-Aug | Excellent | Choppy |
| Sep | Excellent | Choppy |
| Oct | Excellent | Calm |
| Nov-Dec | Poor | Large Waves |
| Pattaya - Expected Weather Conditions | ||
| Months | Underwater | Surface |
| Jan-Mar | Excellent | Calm |
| April | Fair | Large Waves |
| May | Fair | Rain, large waves |
| June-Aug | Good | Choppy, SW |
| Sep | Excellent | Some rain, flat seas |
| Oct | Poor | Rain, storms |
| Nov-Dec | Good | Choppy, NE |
| Note: SW=Southwest Monsoon NE=Northeast Monsoon | ||
| Koh Chang - Expected Weather Conditions | ||
| Months | Underwater | Surface |
| Jan-Mar | Excellent | Calm |
| April | Fair | Large Waves |
| May-Oct | Poor | Rain, large waves, SW |
| Nov-Dec | Good | Choppy, NE |
| Note: SW=Southwest Monsoon NE=Northeast Monsoon | ||
