Yamaten Inc.

Yamaten Inc. (株式会社ヤマテン) is a Japanese weather forecasting company based in Chino, Nagano Prefecture, and is described as the first company in Japan to specialize in mountain meteorology. It was founded on September 5, 2011 by Takayuki Inokuma, a mountain weather forecaster, and holds a weather forecasting business license (Permit No. 172) under Article 17, Paragraph 1 of Japan's Meteorological Service Act. The company's stated mission is to reduce weather-related mountaineering accidents to zero, and its corporate philosophy centers on contributing to safety, disaster prevention, the global environment, and local communities. Yamaten's business spans both consumer and corporate services. For general hikers, it operates the paid membership service 'Yama no Tenki Yoho' (Mountain Weather Forecast), which provides forecasts for 330 mountains nationwide and offers a free seven-day trial upon first registration. For corporate clients, it provides meteorological forecasting and analysis, consulting on weather, avalanches, snow and ice, and disasters, and dispatches instructors for mountain weather courses to organizations such as the Japan Self-Defense Forces, fire departments, and police. Its client list includes travel agencies handling mountain tours, the National Mountaineering Training Institute, NHK, Nippon TV, TBS, the Japanese Alpine Club, and various mountain lodges and local governments. Beyond forecasting, Yamaten runs weather seminars and events, the 'Sora no Hyakumeizan' (Sky's 100 Famous Mountains) project, and publishes a 'Safe Mountaineering Notebook.' Representative Inokuma has authored several books on mountain weather, including 'Yama no Tenki Nyumon' (Introduction to Mountain Weather) published by Yama to Keikokusha. The company also sells branded merchandise such as T-shirts through online shops. Yamaten's forecasts are used in decision-making for events like the Trans Japan Alps Race, where two of the criteria for cancellation, suspension, or course changes are based on Yamaten's services.

Yamaten Inc. was established on September 5, 2011, by Takayuki Inokuma, a mountain weather forecaster, becoming Japan's first weather forecasting company specializing in mountain meteorology. The company is headquartered in Chino City, Nagano Prefecture, at 638-1 Toyohira (Room 402), and holds a weather forecasting business license (Permit No. 172) under Article 17, Paragraph 1 of the Meteorological Service Act. Its founding capital was 9,000,000 yen, and its primary bank is the Yachiyo Bank, Chino Branch. From its inception, Yamaten focused on reducing weather-related mountaineering accidents. Its corporate philosophy emphasizes four contributions: to safety (supporting climbers' safety through weather information from a climber's perspective), to disaster prevention (deepening understanding of nature and disseminating appropriate information), to the global environment, and to local communities. The company's business activities include meteorological forecasting and analysis for mountains and land, consulting on weather, avalanches, snow and ice, and disasters, distribution of mountain weather information via websites and mobile devices, and organizing weather, avalanche, mountaineering, and natural environment courses for educational institutions and mountain organizations. A core consumer offering is the paid membership service 'Yama no Tenki Yoho' (Mountain Weather Forecast), which provides forecasts for 330 mountains nationwide. The service offers a free seven-day trial including the registration day, and a student plan was later introduced allowing group contracts by club (e.g., mountaineering clubs) at discounts of up to 80% compared to individual contracts. The student plan pricing includes annual fees of 6,600 yen for 1–5 users, 13,200 yen for 6–10 users, and 19,800 yen for 11–15 users, with bank transfer payment and receipt issuance supported. Yamaten serves a wide range of corporate clients, including travel agencies handling mountain tours, the National Mountaineering Training Institute, NHK, Nippon TV, TBS, the Japanese Alpine Club, and various mountain lodges and local governments. It also dispatches instructors to organizations such as the Japan Self-Defense Forces, fire departments, and police. The company runs weather seminars and events, the 'Sora no Hyakumeizan' (Sky's 100 Famous Mountains) project—which selects 100 famous mountains by sky and conducts live sky classes across Japan, serialized in the Asahi Shimbun Nagano edition—and publishes a 'Safe Mountaineering Notebook' with three steps for safe climbing, available for free download. Representative Inokuma has authored several books, including 'Yama no Tenki Nyumon' (Introduction to Mountain Weather) from Yama to Keikokusha, 'Tenki no Kotowaza wa Hontou ni Ataru no ka Kangaete Mita' from Bere Publishing, 'Yama no Kantenbo: Kumo ga Oshiete Kureru Yama no Tenki' and 'Yama no Tenki ni Damasareru na!' from Yamakei Shinsho. Yamaten also sells branded merchandise such as T-shirts online. The company's forecasts are used in the Trans Japan Alps Race, where two of the criteria for cancellation, suspension, or course changes are based on Yamaten's services; in the 2020 race held in 2021 due to COVID-19, the race was cancelled on the second day based on these criteria.

• 2011

  Yamaten Inc. founded on September 5 by Takayuki Inokuma in Chino, Nagano, becoming Japan's first mountain meteorology specialist.

• Obtained weather forecasting business license (Permit No. 172) under the Meteorological Service Act.

• Launched paid membership service 'Yama no Tenki Yoho' covering 330 mountains nationwide.

• Introduced student plan for group contracts by mountaineering clubs with up to 80% discount.

• Published 'Yama no Tenki Nyumon' by Takayuki Inokuma through Yama to Keikokusha.

• Started 'Sora no Hyakumeizan' project and serialized in Asahi Shimbun Nagano edition.

Japan's first and leading mountain meteorology specialist, combining professional-grade forecasting accuracy with a safety-first mission for hikers and mountain organizations.

• Yama no Tenki Yoho (Mountain Weather Forecast)

  Paid membership service providing weather forecasts for 330 mountains nationwide, with a free 7-day trial.

• Student Plan

  Group contract plan for mountaineering clubs with annual fees from 6,600 yen for 1–5 users, up to 80% off individual pricing.

• Corporate weather forecasting and consulting

  Meteorological forecasting, analysis, and consulting on weather, avalanches, snow/ice, and disasters for mountain-related organizations.

• Weather seminars and lectures

  Courses and instructor dispatch for educational institutions, mountain organizations, JSDF, fire departments, and police.

• Safe Mountaineering Notebook

  A free downloadable guide summarizing three steps for safe mountaineering.

• Books on mountain weather

  Titles authored by Takayuki Inokuma, including 'Yama no Tenki Nyumon' and 'Yama no Tenki ni Damasareru na!'.

1. 1About | 山岳気象予報 | ヤマテン｜山の天気予報 | 日本yamaten.net
2. 2About | ヤマテン｜山の天気予報 | 日本yamaten.net
3. 3学生プラン | Yamaten企業サイトyamaten.net
4. 4Yamaten Inc. - Wikidatawikidata.org
5. 5ヤマテン - Wikipediaja.wikipedia.org