Oshima

Planning your day in Oshima? Check out the latest weather information, including detailed forecasts and charts provided below.

The climate in Oshima can be described as temperate and humid, with a strong oceanic influence that smooths out temperature fluctuations. Thanks to its location, the island features mild winters, where temperatures rarely drop below 6°C, and warm, yet not exhaustingly hot summers. This makes it an attractive destination all year round, as it lacks the extreme cold typical of more northern regions of Japan.

The seasons transition smoothly, offering travelers a variety of experiences. Spring arrives early here, with pleasant warming starting as early as March and reaching ideal walking temperatures in May. Summer brings warmth, peaking in August with an average temperature of about 26.5°C. Autumn remains pleasant and warm until November, allowing visitors to enjoy nature without needing to bundle up in heavy clothing.

A key feature of the local weather is the relatively high humidity and frequent precipitation. Even in the driest months, the number of rainy days remains significant, and in June and September—which encompass the rainy season and the influence of seasonal winds—the sky is often overcast. Travelers should be prepared for an umbrella to come in handy at any time of year, though the rain here is often refreshing.

The climate in Oshima is marked by its mildness and lack of sharp temperature changes, making the island an attractive destination almost year-round. The coldest months are January and February, when the average air temperature is around 8°C. Winter here is not harsh at all: even on the coldest nights, the thermometer rarely drops below 6°C, and during the day the air warms up to 10°C, allowing you to enjoy walks without needing to bundle up in heavy winter gear.

The summer season brings pleasant warmth, but usually without the sweltering heat characteristic of mainland Japan. The hottest month is traditionally August, with an average temperature of 26.5°C and daytime highs around 28°C. July and September also offer stable warmth, maintaining averages around 24-25°C. This time is ideal for beach holidays and exploring nature, as the weather remains comfortable even in the middle of the day.

A characteristic feature of the local temperature regime is the surprisingly small difference between day and night temperatures—the range of fluctuations during the day often does not exceed 2–3 degrees. Thanks to the influence of the ocean, nights in Oshima remain warm, especially in summer and early autumn. A gradual transition to cooler weather only begins in November, when the average temperature drops to 15°C, preparing the island for its mild winter.

Precipitation on Oshima is unevenly distributed throughout the year, with clearly defined wet and drier periods. The climate here is characterized by a fairly large number of cloudy days: even in the calmest months, it rains at least 9–10 days, so humidity remains noticeable year-round.

The highest amount of precipitation falls in early summer. The peak month for moisture volume is June (about 11 mm), which coincides with Japan's traditional rainy season. However, early autumn leads in terms of weather frequency: September sees a record number of rainy days—averaging about 18 per month. August and October also feature high precipitation frequency (16–17 days), so an umbrella is a must-have accessory during this time of year.

The winter period, on the other hand, is considered the driest season. In December and January, precipitation levels drop to minimum values (2–3 mm), and the number of rainy days falls to 9–10 per month. Since the average temperature in winter stays above +8°C, precipitation occurs mainly as rain; snowfall is untypical for Oshima and happens very rarely.

Spring is a transitional period with moderate moisture. From March to May, rain occurs consistently—about 14 days per month. Travelers should be prepared for changeable weather and brief showers at any time of year, but it is winter that offers the best chance of catching clear skies.

When planning a trip to Oshima Island, it's worth keeping the changeable marine climate in mind. The best solution for any season is layering: this will allow you to easily adapt to temperature fluctuations and the wind that often blows in from the ocean. Be sure to pack comfortable and durable walking shoes, as the island is perfect for long walks and exploring natural attractions.

Winters here are quite mild, with average temperatures around 8–10°C, though it can feel colder due to the humidity and winds, so a windproof jacket or coat will be very useful. In summer, when the air warms up to a comfortable 25–26°C, opt for light, breathable fabrics, but don't forget to bring a hat and sunscreen to protect yourself from the strong sun.

Pay special attention to rain protection: rain on Oshima is a frequent occurrence, with the number of rainy days varying from 9 to 18 per month depending on the season. A compact umbrella or a high-quality raincoat will be your faithful companions, especially if you're planning a trip in June or September. We also recommend bringing a light sweater or hoodie even in summer, as evenings by the sea can be cool.