Waterproof-breathable fabric is necessary (Gore-Tex is better)
Warm Clothing (Down or Fleece Jacket)
It’s necessary even in summer.
Mobile phone is essential to see the map, grasp current location and call for rescue. Be aware that there are many bad connection areas in mountains. Don’t overuse the mobile phone to save battery.
Guide Map is essential but there is no mountain guide map for foreigners in Japan. So please use this site and online map services.
Water Bag and Water
It’s not easy to get drinkable water in mountains. So it’s better to get water befor e climbing. Fortunately, most of tap water is drinkable in Japan.
You can get food at a convenience store or supermarket. There are many convenience stores in Japan, but be careful as it is not in the mountains. If you go to outdoor shop or sports shop, you can buy food specialized for climbing or camp. Calorie Mate Block is a regular item. You can buy it at convenience stores.
Crampon is not item used only for winter. Even in summer, there is residual snow on 3000 m class mountains in Honshu or more than 1500 m class mountains in Hokkaido. If you go there in summer, you should have 6-8 points simple crampons.
Sun Protection Gear
There are blood-sucking insects such as mosquito and black fly in Japanese forest.
Forests in Honshu and Hokkaido are habitats of bears. Hokkaido is habitats of Brown bear which is very big. It’s better to attach bear bell with your backpack so as not to encounter the bear.
Tent that can withstand rain and wind.
Sleeping Bag and Mat
Even in summer, you should have a high thermal insulation sleeping bag.
You cannot bring fuel to airplane, so you have to buy it in Japan. Fuel cartridges of these manufacturers are available in Japan : Coleman, EPIgas, JETBOIL, MSR, Primus, Snow Peak, SOTO. (Boldface brands is especially easy to obtain.)
Mountaineering notification is necessary for smooth rescue activities in case of emergency. In many cases, there are posting boxes for mountaineering notifications at the trail-head or the station near the trail-head. (Find the box with this characters : “登山”.) You should post it before mountaineering. Sample is here.
Call 110 if you need rescue.
110 is the emergency number for police. Mountain rescue is a duty of police. You can talk in Japanese or English. In Japan, rescue cost is self-pay. So it’s better to sign up for insurance.
Do not go to mountain at bad weather
There are risk of slip, getting lost, and freezing to death even in summer.
Do not climb winter mountain unless you are an expert.
Bring a sufficient amount of water.
There are risk of heatstroke especially in summer.
You must check weather forecast before go to mountains.
First, check whether it will be bad weather or not. If it will be bad weather, call off or change the plan.
Second, check the temperature. Most weather forecast sites show only temperatures in the major cities (often in lowlands). So you must estimate the temperature in the mountain using the law that the temperature drops by 0.6 °C per 100 m. You should select the suitable clothes and equipment based on the estimated temperature.
In the mountains, weather tends to be bad in the afternoon. You had better start climbing or trekking early in the morning and finish at 3 pm at the latest.
Weather Forecast Sites
As for the weather in Japan, forecasts by Japanese institutions are most accurate.This page introduce weather forecast sites by Japanese institutions.
Japan National Tourism Organization
Simple and multilingual 10-day forecast.
Japan Meteorological Agency
Weather forecast, weather chart, various data and information of weather, earthquake and volcanoes.
Too much information, difficult to read.
tenki.jp (Japan Weather Association)
Japanese only. Most recommended Japanese weather forecast site. Abundant weather information and commentary.
Japan has an obvious seasonal change. Before planning climbing, you should know characteristics of each seasons.
November, January, February
Winter climate varies from region to region.
The area on the side of the Japan Sea has heavy snow and blizzard almost every day. The average temperature is about 0 ℃ in lowland areas.
By contrast, the area on the side of Pacific is sunny and strong wind blows. This area has only a few snow days in a single season. The average temperature is about 5 ℃ in lowland areas.
If you go to mountains in winter, mountains lower than 1500 m and located in the Pacific side area are better. Mountains on the Japan Sea side or mountains higher than 2000 m are for experts.
March, April, May
In spring, high pressure and low pressure comes alternately, and weather changes cyclically in about one week period. When a high pressure comes from the west, the weather becomes fine. After high pressure goes to east, low pressure approaches and the weather becomes rainy.
The temperature changes rapidly. The temperature may rise or fall by more than 10 ℃ in a few days. So you had better check the weather forecast carefully.
In spring, low altitude mountains will be beautiful with flowers and fresh green. High altitude mountains are coverd with snow.
It is a rainy season called “Tsuyu” or “Baiu” from early June to mid July. The front line stays over the Japanese archipelago and rainy or cloudy days continue. Often it become heavy rain or thunderstorm in the mountain. Sometimes there are sunny days, but prediction is difficult. The rainy season is not suitable for outdoor activities.
After rainy season, sunny days continues. This is the best season for climbing high altitude mountains.
You have to pay attention to heatstroke because summer in japan is very hot and humid. Even in 3000 m class mountains, the temperature is high and you become sweaty. In addition, you also have to pay attention to rapid weather change. Even though it is sunny in the morning, rain and thunderstorms often occur in the afternoon.
Sometimes typhoons approach to Japan in summer. In that case you had better stop climbing.
September, October, December
In autumn, the air dries and the temperature goes down day by day. In 3000 m class mountains in Honshu and 2000 m class mountains in Hokkaido, snow may fall in September.
Weather in autumn changes cyclically like in spring. However, unlike in spring, sometimes heavy rains are brought by typhoons and front lines. You had better stop climbing or trekking when the typhoon approaches or the front line stays over Japan.
Autumn is a nice season for climbing and trekking as the air is clear and beautiful autumn leaves can be seen.
Japan is located in the area where several plates collide each other. Therefore, there are many mountain ranges made by active orogeny. In addition, Japan is located on the Ring of Fire and there are more than 100 active volcanoes.
This page explain the topographic features of mountains by region.
There are many volcanoes in Hokkaido : Daisetsuzan volcanoes which has large lava plateau, Shiretoko volcanoes which is registered as World Heritage sites and has rich primeval forests, and Niseko volcanoes known as the world’s best quality ski resort. Many of these volcanic mountains are large and gentle mountains.
In the south part of Hokkaido Island, there is Hidaka mountain range which was made by orogeny. Difference from other mountains in Hokkaido, Hidaka mountains is steep.
Temperature in Hokkaido is low throughout the year. Therefore trees don’t grow in areas where the elevation is 1000 m or more. These areas are prairie or dwarf pine field.
North Part of Honshu
* Tohoku region
There are mountains height of 1000-2000 m in the north part of Honshu. In this area, O’u mountains goes from north to south. There are also several volcanoes on and around the O’u mountains. Because of heavy snow and low temperature, mountains where the elevation is 1500 m or more are grass-fields.
Central Part of Honshu
* Kanto, Koshin’etsu, Hokuriku, Tokai regions
Central part of Honshu is the most popular areas for mountaineers. This area has Mt.Fuji, the most highest mountain in Japan.
Also there are three 3 famous mountain ranges: Hida, Kiso and Akaishi. These mountain ranges are called “Japan Alps”. They have 3000 m class mountains including Mt. Kita, the 2nd highest mountain in Japan. You can see beautiful view of mountains with snow and rocks in Japan Alps. The elevation of the mountains is not so high in the world. However, due to the steep and severe climate, difficulty is never low.
In Central part of Honshu, there are many 1000-2000 m class mountains besides Japan Alps. These mountains are covered with hardwood trees such as beech and coniferous trees such as cedars.
Southwest Part of Honshu, Shikoku
* Kansai, Chugoku, Shikoku regions
This area has 1000 m class mountains covered with rich forest. There are few volcanoes.
There are many mountains that have been the subject of mountain beliefs since the ancient times, including the Kii mountains, and you can also learn Japanese religion and culture.
Kyushu region has many volcano, so it was called “Hinokuni” (Japanese : Land of Fire) in the ancient time.
In this area, Mt. Aso which has the world’s largest caldera, and Sakurajima which frequently eruptions are famous.
Kyushu region has many islands. Yakushima island located on the south side of Kyushu is a popular spot for forest walking. At the foot of Mt. Miyanoura in the island, there are deep forests where huge cedar and plenty of moss grows.