Ishigaki and the Yaeyama islands have a tropical rainforest climate with long summers and very mild winters. It is humid all year round, but the rainy season is one of the shortest in Japan. The most popular season to visit is summer and early autumn (June to October.) To avoid the crowds, it is strongly recommended to avoid the Japanese holidays such as Golden Week and the school summer vacation.

table of Ishigaki mean temperaturesMean temperatures for Ishigaki by JMA, 1981-2010. Some numbers have been rounded off for ease of reference.

The guide below is a general summary of the weather in Ishigaki and the Yaeyama islands. As in any place, there will be cold years, hot years, rainy years, sometimes you can find summer in winter, sometimes winter will come early. If your goal is to walk around on a sunny beach in flip-flops, high season (June-October) is the best time to go.

January – February (Winter)

If you are lucky you can have sunny days with temperatures above 20°C daytime, however, these months have many periods of rainy and windy weather with daytime temperatures around 15°C. When the sun is out it is perfect weather to go hiking or walk around in a T-shirt on an empty beach. Evenings will be cold so make sure to pack a jacket or a warm sweater.
Since the ocean is fairly warm all year round you can do watersports if you wear a thicker wetsuit.
In February, the first cherry blossoms in Japan will start to bloom.

March – April  (Spring)

The official beach opening ceremony is usually held in mid-March and it will start to get warmer and warmer on the islands. When the wind blows it can still feel quite cold, especially in the evenings, so it is good to bring a jacket or warmer sweater. There will be more sunny days with good weather for hiking.

May – June (early Summer)

The rainy season usually hits in May, it is the shortest in Japan and only lasts 2-4 weeks. Be prepared for the occasional tropical downpour out of nowhere but there are many warm sunny hours, often days, between the rains. It is the most humid season in Ishigaki. In June the true summer is finally here!

July – August (Summer)

Hot sunny days and the emerald blue ocean. Life is good!

September – October (Summer)

Hot sunny days and the emerald blue ocean. Life is good!
Unless a typhoon blows by of course, September is the month with the highest risk of typhoons. The island will start cooling down again by the end of October

November – December (Autumn)

In the beginning of November there is still a good chance for warm summer days but, by the end of the month, it will start to get colder and the beaches officially close (nobody will stop you from swimming though). The ocean stays fairly warm until the middle of December. Depending on the weather, November could feel chilly with strong winds and by December you might want to bring a warm sweater for the evening.

Typhoon Season

Typhoons season is from June to October. The strength and number of typhoons vary every year with an average of 2-3. Be sure to follow safety advice given by your accommodation and stay indoors. Buying instant cup noodles for food is a good idea if there is no restaurant inside the hotel. Usually, a typhoon will pass within one day but it could also be around longer.

If a typhoon hits or passes close to Ishigaki boats and flights will be canceled. If you have a connecting flight, make sure to check what rules apply if you miss your connection. You could also plan your trip so that you have some days in between as a buffer. If your flight from Ishigaki gets canceled because of a typhoon, airlines will generally put you on the next available flight. Always check the specific conditions that apply to your flight at the time of booking.

For the latest weather forecasts and typhoon warnings, Japan Meteorological Agency has information in English.