Miyanoura, located on Yakushima Island, features a humid subtropical climate with abundant rainfall year-round. Summers are warm, humid, and often windy, while winters are mild but can be extremely windy and clear. The region is renowned for its lush forests, frequent cloud cover, and dramatic seasonal shifts in weather and daylight.
Miyanoura’s climate is shaped by its coastal island setting and proximity to the mountains of Yakushima. The area experiences warm, humid, and often windy summers, with average highs reaching around 30°C in August and lows near 24°C. Rainfall is significant throughout the year, peaking in June with over 770 mm, making Yakushima one of the rainiest places in Japan. The rainy season (tsuyu) spans from June to early July, bringing persistent showers, high humidity, and lush green landscapes. Typhoons can occasionally impact the area from late summer to early autumn, bringing strong winds and heavy rain.
Winters in Miyanoura are mild at sea level, with average highs of 14–16°C and lows around 8–10°C, though the season is characterized by extremely windy conditions and mostly clear skies. Snow is rare on the coast but can be seen in the island’s mountainous interior. Spring and autumn offer a mix of sunshine and rain, with temperatures ranging from 17°C to 24°C. Daylight varies from about 10 hours in winter to over 14 hours in summer, and the sunniest months are May and August, each with over 10 hours of sunshine per day. Cloud cover is frequent, especially in winter, but visibility remains high year-round.
Miyanoura’s weather is dynamic, with frequent changes between sun, clouds, and rain. The abundant rainfall supports ancient cedar forests and a UNESCO World Heritage landscape, making the climate a defining feature of the region’s natural beauty.
| Average climate data for Miyanoura, Japan | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°F) | 59 | 60 | 63 | 68 | 73 | 77 | 82 | 84 | 82 | 76 | 70 | 63 | 84 |
| Average minimum temperature (°F) | 55 | 56 | 59 | 64 | 70 | 75 | 80 | 82 | 80 | 74 | 67 | 58 | 55 |
| Average precipitation (inch) | 3 | 4 | 4 | 4 | 4 | 11 | 6 | 4 | 5 | 5 | 4 | 4 | 57 |
| Average rainfall days (days) | 20 | 19 | 18 | 16 | 15 | 22 | 18 | 18 | 19 | 17 | 18 | 22 | 223 |
| Average relative humidity (%) | 69 | 71 | 70 | 70 | 74 | 82 | 85 | 79 | 78 | 72 | 69 | 71 | 74 |
| Average wind speed (mph) | 18 | 18 | 17 | 15 | 13 | 13 | 12 | 13 | 14 | 17 | 15 | 19 | 15 |
| Average water temperature (°F) | 70 | 68 | 70 | 72 | 75 | 77 | 83 | 84 | 82 | 79 | 75 | 71 | 76 |
| Average daily daylight hours (h) | 10 | 11 | 12 | 12 | 13 | 14 | 13 | 13 | 12 | 11 | 10 | 10 | 12 |
| Average daily sunshine hours (h) | 4 | 5 | 6 | 8 | 8 | 7 | 9 | 10 | 8 | 5 | 5 | 4 | 7 |
| Average cloud coverage (%) | 56 | 56 | 49 | 43 | 46 | 56 | 38 | 36 | 42 | 44 | 44 | 57 | 47 |
| Average UV index | 4 | 4 | 4 | 5 | 6 | 6 | 7 | 7 | 7 | 5 | 4 | 3 | 5 |
The best times to visit Miyanoura are in spring (April to May) and autumn (October to November). During these months, rainfall is lower, temperatures are comfortable, and the island’s forests are at their most vibrant. These seasons are ideal for hiking, sightseeing, and enjoying Yakushima’s natural beauty with fewer weather disruptions.
The least favorable time to visit Miyanoura is during the rainy season in June and early July, when rainfall is at its peak and outdoor activities can be challenging. Late summer (August–September) can also bring typhoons, high humidity, and strong winds, occasionally disrupting travel and hiking plans.
Miyanoura receives over 4,600 mm of rain annually, with June being the wettest month. Rain is frequent year-round, making the region one of the rainiest in Japan and supporting its lush, ancient forests.
Average highs range from 14–16°C in winter to 30°C in summer. Lows are around 8–10°C in winter and 24°C in summer. The climate is mild year-round at sea level, with greater variation in the mountains.
Snow is rare at sea level in Miyanoura, but the mountains of Yakushima can see snow in winter. Hikers should be prepared for cold and potentially snowy conditions at higher elevations.
The rainy season (tsuyu) occurs from June to early July, with June being the wettest month. Expect persistent showers, high humidity, and lush green landscapes during this period.
Yes, typhoons can affect Miyanoura from August to September, bringing strong winds and heavy rain. Travelers should monitor forecasts and be prepared for possible disruptions during this season.
Pack rain gear year-round, including a waterproof jacket and sturdy shoes. Bring layers for cooler evenings, especially in spring and winter, and a windproof jacket for winter’s strong breezes.
Sunshine hours peak in May and August, with over 10 hours per day. Winter months are cloudier, but clear days are common. Daylight ranges from about 10 hours in winter to 14 hours in summer.
The warmest month, with the highest average maximum temperature, is August (83.9 °F). The month with the lowest average maximum temperature is January (58.7 °F). Overall, the average maximum temperature over the whole year is 71.4 °F.
The month with the highest average minimum temperature is August (82.2 °F). The coldest month, with the lowest average minimum temperature, is January (54.7 °F). Overall, the average minimum temperature over the whole year is 68.3 °F.
The month with the highest average water temperature is August (84.3 °F). The month with the lowest average water temperature is February (67.9 °F). Overall, the average water temperature over the whole year is 75.5 °F.
The wettest month, with the highest amount of precipitation, is June (11.3 inch). The driest month, with the least amount of precipitation, is January (3.2 inch). Over the whole year there are 57.2 inch of rainfall on average.
The month with the most days of rain is June (21.9 days). The month with the fewest days of rain is May (14.7 days). Over the whole year there are 222.5 days of rain on average.
The month with the highest average relative humidity is July (84.8 %). The month with the lowest average relative humidity is January (68.9 %). The overall average relative humidity over the whole year is 74.2 %.
The windiest month, with the highest average wind speed, is December (18.5 mph). The calmest month, with the lowest average wind speed, is July (11.9 mph). The overall average wind speed over the whole year is 15.3 mph.
The month with the cloudiest skies, so the highest cloud coverage, is December (56.8 %). The month with the clearest skies, so the lowest cloud coverage, is August (35.9 %). Over the whole year there is an average cloud coverage of 47.3 %.
The month with the longest days, so the most daylight, is June (Average daylight: 14 h). The month with the shortest days, so the least daylight, is December (Average daylight: 10 h). Over the whole year there are 11.8 h of daylight per day on average.
The month with the most sunshine per day is August (Average sunshine: 10 h). The month with the least sunshine per day is January (Average sunshine: 4 h). Over the whole year there are 6.6 h of sunlight per day on average.
The months with the highest average UV index are July, August and September (UV index: 7). The month with the lowest average UV index is December (UV index: 3). Over the whole year the average UV index is 5.2.
