Quote: ‘It rains 35 days a month on Yakushima island’ in Kushu, Japan (九州の屋久島では、ひと月に35日雨が降る。)


Yakushima island is one of very popular places to visit in Japan, especially among nature lovers, avid mountain climers and hikers.

I would like to share some interesting facts about this island in this article.

Yakushima macaque

1. Basic information about Yakushima island

Yakushima island is located about 60 km south of Kyushu island and 135km south of Kagoshima city.

Just under 13,000 people live there(as of 2016).

The length of the perimeter of the island is about 126km.

It is the 7th largenst island in Japan.


2. Forests on Yakushima island

Part of Yakushima island was designated as UNESCO site in 1993, because of its valuable premival forests.

It is said that about 70 percent of botanical species of Japan can be found on Yakushima island.

The island has some vertical distribution zones of plants on the mountains with steep sides.

Moss-coverd forest(Shiratani-unsui-kyo)

A path in Shiratani-unsui kyo


3.Rainfall on Yakushima island

It is said that Yakushima is one of the places with largest precipitation in Japan.

The average annual rainfall on Yakushima can reach about 44cm/17inches on the flat, 75cm/30 inches in the mountains.

(Average annual rainfall in Japan is 17cm/6.7inches.)

Japanese novelist Fumiko Hayashi wrote in her novel that ‘ It rains 35days on Yakushima island‘, emphasizing the large amount of rain the island can have.


Ohko-no-taki waterfall with abundant water


4.How Yakushima island was created

Yakushima was created by an ocean floor upheaval about 15,000,000 years ago.

As a result, the surface of the land is quite rocky and the depth of the soil is rather shallow.

The highest peak on the island is ‘Mt. Miyanoura-dake’,1,936meters / 6,351ft.

Rocky surface of the ground

Mt Mocchomu-dake

Tenchuseki rock on Mt. Tachu


5. Yakusugi cedar trees

Yakushima island is also well know for its giant Yakusugi cedar trees.

Cedar trees over 1,000 years old on Yakushima island is defined as ‘Yakusugi cedars’.

Yakusugi cedars grow extremely slow as the soil is shallow and not much nutrition is in it, which actually makes the trees stronger as the annual rings have narrow spaces.

It is said that the longest lifespan for cedars is usually up to 500 years old, but Yakusugi cedars can live much longer for the reason above.

Three-thousand-year-old Yakusugi cedar ( Kigen-Sugi ) and some epiphytes

Eighteen-hundred-year-old cedar tree(Buddha sugi cedar)


6. Other interesting trees

Yamaguruma (Wheel tree) as epiphytes:

In a deep forest, trees compete to get as much sunlight as possible.

As a result, giant cedar trees on Yakushima island can get some tangling trees around their trunk.

These tangling trees are called ‘Yamaguruma’ in Japanese, ‘Wheel trees’ in English.

Yamaguruma(wheel tree)


Himeshara (Stewartia monadelpha) :

Reddish trees stand out in the forest of Yakusugi Land.

They are called ‘Himeshara’ in Japanese, ‘Stewartia monadelpha’ in English.

The barks flake in winter. You can find this tree in western Japan, including on Yakushima island.



Himeshara up close


Yakutane-goyo pine (Pinus amamiana):

Yakutane-goyo pine is listed as endangered species and is endemic to Yaushima and Tanegashima island(※).

‘Yakutane’ is the combination word of ‘Yakushima’ and ‘Tanegashima’ and ‘goyo’ means ‘five needles’.

They grow mainly on the mountain ridges where there is much sunlight, and can grow as tall as 25 meteres.

They contain much resin so dugouts(canoes) were made of Yakutane-goyo pines in the past.

Yakutane-goyo pine can be found at the altitude between 300meters and 800 meters.

Some of them are becoming withered and have no leaves but white trunks and branches remain, which is visable from the distance(as shown in the picture below).

Withered Yakutane-goyo pines on mountain ridges

(※)Tanegashima island is about 40km south of Kushu island and 18km east of Yakushima island. Tanegashima island is well know in Japan for the place where first guns were introduced in 1543 and Christianity as well  in 1549 both by Portugese.


Beautiful moss with water drops:

Yakushima island is a paradise for moss as it rains a lot.

Beautiful moss up close


Genzui (Euscaphis japonica):

The tree bears the red fruits with black seeds from September.

‘Genzui’ in Japanese, ‘Euscaphis japonica’ in English