Winter in Okinawa's Waters
December through February is Okinawa's coolest period, though it remains mild compared to mainland Japan. Strong north winds make the wind chill feel cooler than the actual temperature. Still, water temperatures hold at 20-22°C (68-72°F) — perfectly diveable with a thick wetsuit or drysuit. The crown jewel of winter is whale watching: humpback whales migrate to the Kerama waters from January through March for breeding and calving. This is an exclusive Okinawa winter experience. With the fewest tourists of the year, it is also the cheapest season across the board.
Winter Weather Data
| Month | calendar.air_temp | Water Temp | calendar.rainfall | calendar.wetsuit |
|---|---|---|---|---|
| December | 15-21°C (59-70°F) | 22-23°C (72-73°F) | 103mm (approx. 9 rainy days) | 5mm full suit + hood recommended |
| January | 14-19°C (57-66°F) | 20-21°C (68-70°F) | 107mm (approx. 10 rainy days) | 5mm full suit + hood vest, or drysuit |
| February | 14-20°C (57-68°F) | 20-21°C (68-70°F) | 120mm (approx. 10 rainy days) | 5mm full suit + hood vest, or drysuit |
Recommended Winter Activities
Whale Watching
January to March only. Humpback whales migrate to Kerama waters for breeding and calving. Encounter rates reportedly exceed 98%. Half-day tours from Naha are most popular.
Winter Fun Diving
Winter brings exceptional visibility — often exceeding 30 meters. Chance encounters with manta rays and hammerhead sharks are a winter bonus.
Underwater Photography Diving
Crystal-clear winter waters are ideal for photo diving. It is also peak nudibranch season, a treat for macro photographers.
Blue Cave Introductory Dive
Available even in winter. With fewer visitors, you may enjoy near one-on-one time with your guide.
Glass-Bottom Boat
Enjoy the underwater world without getting wet — ideal for those who prefer to stay warm or for families with small children.
Winter Booking & Preparation Tips
- Whale watching is popular — book early for the New Year holiday period
- On windy days the boat will rock considerably, so bring seasickness medication
- When choosing a dive shop, confirm whether drysuit rental is available
- A boat coat or windproof jacket is very useful for staying warm above water
- Winter is the cheapest season — flights, hotels, and activities are all at their lowest prices
- Sea conditions can change rapidly with weather, so have backup dates or alternative plans ready