曇天の額平川コース。渡渉で濡れ低体温症に注意

Horoshiri-dake summit is cloudy with a perceived temperature of 4.8 degrees Celsius. There is an 11-degree temperature difference from the base, indicating a persistent chill even during the day. Conditions will transition to partly cloudy, with temperatures rising to 11.9 degrees, but the perceived temperature can drop on ridges and in the cirque terrain due to light winds. Visibility is limited to 1.4km, necessitating careful route confirmation when navigating the cirque.

The Nukabiragawa Course, with over 20 river crossings, will remain wet to muddy throughout the day. Although precipitation is minimal, the humid environment typical of the deep primeval forests of the Hidaka Mountains means getting wet is unavoidable. River shoes are essential, ensuring secure footing.

Given the consistently low perceived temperatures, there is a high risk of hypothermia if you get wet during river crossings. A fast-drying base layer, an insulating mid-layer like fleece, and waterproof-breathable outer layers are crucial. Immediately put on extra insulation during breaks. While the risk of thunderstorms and strong winds is low, this is a dense bear habitat, so do not neglect bear bells and spray. A forecast of light drizzle around 6 PM suggests an early finish to your activities is advisable.