Kohama Island (Okinawa)
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Learn about the temperature and clothing for Kohama Island, Okinawa, a healing island

Kohama Island is a small island with a circumference of about 16 km, located about a 25-minute high-speed boat ride from Ishigaki Island, which is about 350 km southwest of the main island of Okinawa. It is known nationwide as the setting for the NHK serial TV drama "Churasan," and "chura" (beautiful) scenery spreads across the entire island. The cobalt blue sea, sugarcane fields, and the panoramic view of the surrounding remote islands from the observatory in the center of the island provide healing through numerous original Okinawan landscapes.
Kohama Island has the same subtropical climate as Ishigaki Island. Even in winter, the temperature rarely drops below 10°C, and it is warm throughout the year. From late spring onwards, you will feel the humidity unique to the subtropics, but the pleasant sea breeze mitigates the heat. Even so, the sunlight is strong, and the amount of UV radiation can be twice that of Tokyo at its peak. Be sure to take measures against sunburn.
Also, you need to be careful about typhoons. Because it is called "Typhoon Ginza" due to the high number of approaches, it is recommended to check typhoon information when planning your trip.

Kohama Island Temperature Graph

About the temperature and clothing for spring (March–May) on Kohama Island
About the temperature and clothing for summer (June–August) on Kohama Island
About temperatures and clothing for autumn (September–November) on Kohama Island
About temperatures and clothing for winter (December–February) on Kohama Island

In March, the average temperature is about 21°C, which is as warm as late May in Tokyo. While there are days in early March when you might need a hoodie or similar outer layer, by mid-month when the beaches open, the weather is warm enough for short sleeves. However, the sea water is still cold, so if you want to enjoy activities, SUP (stand-up paddleboarding) and canoeing are recommended.
In April, the average temperature rises to 23°C, and in May, it climbs to nearly 26°C. This is the perfect season to enjoy strolling around the lush green island. Be sure to use a bicycle to get around the small island. The exhilaration of riding through the wind on "Sugar Road," a single path that stretches through landscapes of sugarcane fields and pastures, is irresistible. However, since the sunlight is strong even in spring, be sure to bring a hat, sunscreen, and a long-sleeved shirt when you go out.

The rainy season in Okinawa Prefecture is characterized by short bursts of subtropical, waterfall-like rain (squalls), and Kohama Island is no exception. The rainy season typically lasts from mid-May to mid-June. With an average minimum temperature of 27°C, you won't feel the chill associated with the rainy season on the main island of Japan, so you can dress lightly.
In July and August, when UV levels are at their highest for the year, the average maximum temperature exceeds 32°C. Sun protection and heatstroke prevention are essential when going out, and since you will sweat a lot due to the humidity, it is convenient to carry a spare T-shirt.
Summer on Kohama Island, surrounded by one of Japan's largest coral reef groups, is the best season for marine activities. While snorkeling or scuba diving, you can see colorful tropical fish living in the coral reef forests, and if you are lucky, you might even encounter manta rays.
Also, since many typhoons approach in August, it is a good idea to check typhoon information frequently for peace of mind.

The average maximum temperature in September is 31.5°C. The heat that makes you sweat even in short sleeves continues.
By October, the average temperature drops to about 26°C, and the humidity subsides. This is a time when there are many sunny days, making it easy to plan your trip. It is the perfect time to visit "Hamajima," a phantom island where a white sandy beach appears above the sea only when the tide is low. If the weather is good, there are days when the temperature reaches 30°C or higher, so you can fully enjoy marine activities amidst a 360-degree panoramic view of emerald green waters.
The island's biggest festival, "Kichigan," where folk dances like "Daatuda" are performed, takes place from late October to early November. By this time, the mornings and evenings become cooler, and a light jacket becomes necessary. If you are going out to observe the starry sky, where the Southern Cross is beautiful, be sure to bring a hoodie or jacket.

The average temperature from December to February is about 19°C. With an average high of around 22°C, it is warm, and compared to other seasons, the UV levels are relatively low, making it a comfortable time to visit. You can get by in short sleeves during the day, but as January approaches, the north wind picks up, and on cold, windy days, the perceived temperature can feel like 10°C or lower.
From late December to the end of January, when the air is clear, the sunsets that Kohama Island is proud of look even more beautiful. When heading out to the beach or sightseeing around the island, it is a good idea to bring a windbreaker or a thick cardigan to protect yourself from the wind chill.
By late January, the vibrant, deep pink Kanhizakura (Taiwan cherry) blossoms begin to bloom, creating a colorful landscape. In early February, when they are in full bloom, the weather is pleasant, making it a comfortable time for cherry blossom viewing. There are fewer tourists during this period, allowing you to spend a peaceful time enjoying the unique charm of Kohama Island in your own way, whether by relaxing on the beach or strolling through the village.

*The information provided is current as of the date of the article's update. Please check in advance as it may be subject to change.