Weather in Kumejima

Find out what weather awaits you in Kumejima right now to make your trip as comfortable as possible. In this section, you will find up-to-date weather reports, detailed charts, and a forecast for the near future.

Kumejima welcomes travellers with a mild subtropical climate, ensuring it remains warm and comfortable here almost all year round. The island is ideal for those looking to escape the harsh cold: even in the coolest winter months, such as January and February, the average air temperature holds at +18...+19°C, reminiscent of a pleasant spring.

Summer on the island is hot and humid, with temperatures reaching +28...+29°C, creating perfect conditions for a beach holiday. However, when planning your trip, it is worth considering the seasonality of rainfall. June stands out as the wettest month — the period of the so-called "rainy season", when the number of inclement days can reach twenty-one. During the rest of the year, the weather is more stable, and the sea breeze makes the heat easier to bear.

The climate on the island of Kumejima is characterised by the mildness and stability typical of the subtropical zone. There is practically no concept of a harsh winter here: even in the coldest months of the year, January and February, the average air temperature remains at a comfortable level of around +18.5°C...+18.8°C. The annual temperature range is quite smooth, without sudden spikes, reaching its peak in August, when the air warms up to an average of +28.5°C.

The summer period, beginning in June, brings consistent warmth. During this time, the temperature stays steadily in the range of +26°C...+29°C. Although June is a warm month (+26.6°C), it is distinguished by a high number of rainy days, which is typical for the rainy season in this region of Japan. By August, the hottest weather sets in, yet thanks to the maritime climate, extreme heat is rare here, and temperatures seldom exceed +30°C.

A surprising feature of Kumejima's temperature regime is the minimal difference between daytime and nighttime figures. Diurnal fluctuations are extremely insignificant and often amount to just 1–1.5 degrees. For example, in August, the average minimum (+27.9°C) is almost indistinguishable from the maximum (+29.2°C). This means that nights here are very warm, and one should not expect significant coolness after sunset during the summer months.

Precipitation on the island of Kumejima falls quite frequently but is distributed unevenly throughout the year. Given the warm climate, where even in winter months the temperature does not drop below 17°C, it rains exclusively here, and snow never occurs. The nature of precipitation varies from light drizzle to more noticeable rains, especially in early summer.

The wettest month of the year is June: the highest volume of precipitation (about 14 mm) and the maximum number of rainy days — 21 — are recorded at this time. This means that in June, it can rain almost daily. The second peak in humidity occurs in September, when about 19 days with precipitation are observed.

The relatively dry season is not very pronounced, as rain is possible at any time of the year. The lowest number of rainy days falls in July (12 days) and November (13 days). In winter and spring, although the volume of precipitation is minimal (only 4–5 mm per month), it rains quite often — approximately 15–16 days per month. Therefore, travellers are recommended to always have an umbrella or a light raincoat with them, regardless of the chosen season.

When packing for Kumejima, you should plan for the island's subtropical climate: it is warm and humid for most of the year. For a trip during the summer months, from May to October, when temperatures hover around 24–28°C, opt for light and breathable clothing made from natural fabrics such as cotton or linen. Be sure to bring swimwear, sunglasses, and a hat, as the sun here can be very intense. Considering that June is the wettest month (about 21 rainy days), a light raincoat or umbrella will be absolutely essential.

The winter period and the off-season (from November to April) on the island are very mild, with temperatures rarely dropping below 17–18°C; however, due to sea winds, it may feel cooler. At this time of year, the principle of layering works best: bring t-shirts over which you can wear a hoodie, cardigan, or fleece jacket. A windbreaker will be a wardrobe staple, protecting you from the breeze during coastal walks and the evening cool.

Regardless of the season, to explore the natural beauty of Kumejima, you will need comfortable and worn-in walking shoes, such as trainers, as well as sandals for the beach. Since statistics show between 12 and 21 rainy days monthly throughout the year, it is worth keeping a compact folding umbrella in your backpack at all times. Also, do not forget sunscreen with a high protection factor, which will come in handy even in cloudy weather.