独立峰 穏やかな日中。夜間の冷え込みに備えよ

Current conditions at the summit of Mount Yotei are cloudy with a temperature of 12.2℃, feeling like 10.1℃. Winds are light from the southeast at 1.58m/s with gusts up to 6.4m/s, and visibility is excellent at over 20km. The day will remain mostly cloudy to partly cloudy with no precipitation expected. Temperatures are forecast to be stable between 13℃ and 15℃ until around 3 PM. Snow depth is 0cm, indicating generally dry to wet trail conditions. Above the tree line at 1400m, exposed rocky terrain can be expected. Crampons or microspikes are not necessary, but carrying rain gear is advised as a precaution. With a felt temperature of 10.1℃, a base layer, light mid-layer, and a softshell or light outer layer for wind protection should suffice.

However, a rapid temperature drop is identified as a risk. Summit temperatures are projected to fall from a daytime peak of 15℃ to 0.5℃ by early morning, a drop of over 13℃. While the winds are relatively calm today, the significant overnight temperature decrease poses a serious hypothermia risk, especially considering Mount Yotei's nature as an isolated peak prone to sudden weather changes. For those traversing routes like Hirafu or Makari that ascend above the tree line, ensure you carry extra warm layers such as thick down jackets or fleece. When traversing the crater rim (Ohachi-meguri) around the summit crater, be vigilant for the risk of falling from the rim and watch your footing carefully.

The risk of lightning is low due to zero precipitation probability. Maximum gusts of 10.7m/s during the day are not prohibitive for activity, but be mindful of the isolated peak's characteristic updrafts. While the risk of hypothermia is low during the day, it becomes a significant concern overnight as felt temperatures will drop close to freezing. Overnight activity is not advisable. A descent before sunset is strongly recommended.