曇り空の下 稜線は穏やか 行動は慎重に

Summit conditions are cloudy, with a current temperature of 11.7℃ and a felt temperature of 10.4℃. The forecast suggests temperatures will rise to the mid-14s℃ during the day. However, steady winds of 3 to 4 m/s and gusts potentially exceeding 11 m/s, combined with over 90% humidity, mean the actual felt temperature will be significantly lower, potentially dropping to single digits during strong gusts.
With no precipitation, widespread mud is not anticipated. Nevertheless, high humidity and cloudy skies will maintain generally wet ground conditions. Extreme caution is paramount on the fragile volcanic scree from the 9th station to the summit. Wet surfaces here drastically increase the risk of slipping and dislodging loose rocks. Every step must be deliberate.
For layering, a quick-drying base layer is essential. Pair this with a fleece or similar insulating mid-layer. A waterproof-breathable outer shell is mandatory. Additionally, always carry gloves, a warm hat, and spare insulating layers to mitigate the effects of wind chill and any sudden precipitation.
Although automated risk assessment has not flagged any severe alerts, Mount Rishiri, as an isolated peak highly exposed to sea winds, demands constant vigilance for rapid weather shifts. Gusts are predicted to intensify in the afternoon, making an early start and a timely descent highly advisable to avoid deteriorating conditions.