When To Go · Destination Guide

Koh Tao

Warm-water pinnacles, a signature wreck, and snorkel bays in Thailand's Turtle Island dive town

Updated Jan 23, 2026 • 15 sources

When to go

Best time to visit Koh Tao

Diving is possible yearround, but conditions vary.

Best overall window

Warm water 28°C to 30°C, visibility often 15 m to 25 m, generally calmer seas.

Outside that window

More windwaves and heavier rain possible. Visibility can drop to 5 m to 10 m, and ferry schedules are more disruptionprone.

Start with the overall answer, then switch only when scuba, freedive, snorkel, or topside timing changes the trip in a meaningful way.

The overall row stays visible so you can compare it against the currently selected scope.

BestGoodTradeoffsMore variable

Scope	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Overall	Overall - Jan: Tradeoffs	Overall - Feb: Good	Overall - Mar: Best	Overall - Apr: Best	Overall - May: Best	Overall - Jun: Best	Overall - Jul: Best	Overall - Aug: Best	Overall - Sep: Best	Overall - Oct: Good	Overall - Nov: Tradeoffs	Overall - Dec: Tradeoffs

These do not replace the overall planner. Use them only if a specific animal or event is driving your trip dates.

Whale shark sightings on deep pinnacles
Best for Scuba
Mar to Jul
JanFebMarAprMayJunJulAugSepOctNovDec
Sightings are never guaranteed, but local reports most often cluster in the warmer, calmer season.
Sea turtle nesting and hatchlings (variable)
Best for Snorkel, Scuba
Aug to Nov
JanFebMarAprMayJunJulAugSepOctNovDec
Koh Tao is known as a turtle breeding area, but nesting timing varies by year and beach.
Blacktip reef sharks in shallow bays
Best for Snorkel
Mar to Aug
JanFebMarAprMayJunJulAugSepOctNovDec
Shark Bay (Ao Thian Og) is frequently mentioned for blacktip reef shark sightings in the shallows.
Songkran (Thai New Year) atmosphere
Best for Topside
Apr
JanFebMarAprMayJunJulAugSepOctNovDec
Thailand's Songkran period brings waterfight fun and holiday energy.
Full Moon Party connection (Koh Phangan)
Best for Topside
Year-round
JanFebMarAprMayJunJulAugSepOctNovDec
Koh Tao is an easy base for a Koh Phangan side trip.
Gulf wind-wave advisories
Best for Scuba, Freedive, Snorkel, Topside
Nov to Jan
JanFebMarAprMayJunJulAugSepOctNovDec
Northeast monsoon surges can create strong windwaves in the Gulf of Thailand.

Koh Tao is diveable yearround, but the October to December period is the most variable for sea crossings.

Feb, Oct: Transition months. February can be clear and comfortable, while October can swing between calm weeks and the start of heavier rain.
Nov to Jan: More wind-waves and heavier rain possible. Visibility can drop to 5 m to 10 m, and ferry schedules are more disruption-prone.

Built from climate references, access rules, and destination operators. Wildlife timing and route flexibility can shift year to year.