Yamaten Mountain Weather Forecast
Produced by Yamaten Inc.

Precaution for use

The weather forecast at the top of the mountain (Mt. Weather Forecast) provided for members at this "Yamaten Mountain Weather Forecast" is original information based on observation / prediction data released by the Japan Meteorological Agency. For this reason, Mt.WF may be different from the weather forecast released by the Japan Meteorological Agency. Also, the alerts delivered at Mt. Weather Forecast are completely different from the warnings and alerts released by the Japan Meteorological Agency. Please confirm warnings and alerts released by the Japan Meteorological Agency when climbing.

Furthermore, since this information on this website is not intended for general use, you cannot provide the "Yamaten" to third parties, such as forwarding this information by email. Please be aware that doing so will be in violation of the Meteorological Service Act. Also, please be sure to read "Terms of use" and "Cautions in using weather forecasts" below.

In addition, the Mt. Weather Forecast is information analyzed from the weather at the summit over the past several years based on a live camera, information from mountain huts, reports from mountain climbers, satellite images, radar observations, the horizontal map of precipitation as analyzed by radar, and surface observations by Yamaten, Inc. It is a weather forecast (hereinafter referred to as a "calculation result") that is compared with the numerical forecast result released by the Japan Meteorological Agency and modified using our original calculation formula for mountain weather.

In addition, announced calculation results are modified based on the climbing experiences, forecast experience, and forecast technology of the weather forecaster while considering the topography of each mountain. However, the forecasting method differs between the representative points in each mountainous area and other mountains.

Therefore, when using mountain forecasts other than the representative point, please be sure to check the weather forecast of the representative point in that mountainous area.

The wind speed reported in the "Yamaten" is the average value for every 10 minutes at 0 o'clock, 6 o'clock, 12 o'clock, and 18 o'clock. Please be aware that the instantaneous maximum wind speed (maximum instantaneous wind speed) may be approximately 1.5 to 2.0 times larger than the wind speed value reported in the "Yamaten".

Furthermore, since the weather of the mountain may change drastically, the forecast may be quite different from the actual situation. Therefore, we hope that you will not only check this "Yamaten" but also use the information effectively according to actual weather conditions by checking the surface weather chart, the upper level weather chart, the satellite image, the forecasted weather chart, etc.

We do not assume any responsibility as to the result of the weather forecast at the "Yamaten" or any your actions based on the information on our homepage. In addition, please see the latest information by clicking the "Update" button of your Web browser software when you use information from "Yamaten".

However, due to system operation, you may not be able to see some or all of the content, and this information may not be updated. Therefore, please check publication time of information, and use the information carefully. Please understand in advance that contents of our website may be changed or deleted and that URL of our website may be changed without notice.

This website posts various information on the premise that you will see it on common Web browser software. Please do not collect weather data or other information regularly and automatically using automatic patrol software since our Web server may be overloaded.

In addition, there are areas where radio waves, such as for mobile phones, cannot be received in mountains. Therefore, please be sure to check the weather information, live weather charts, forecasted weather charts, and live cameras (only on mountains where cameras are set up) on our website, the homepage of the Japan Meteorological Agency, and television weather forecasts before your departure.