利尻山 午後から風強まる。気温低下に備えよ

Mount Rishiri summit is currently cloudy with a temperature of 3.2℃, feeling like -0.8℃. East winds are blowing with gusts up to 9.4m/s. There is a significant 9.4℃ temperature difference between the summit and the base, indicating colder conditions at higher elevations. While no precipitation is expected throughout the day, winds are forecast to strengthen in the afternoon, leading to a further drop in the perceived temperature.

By 9:00 AM, the temperature will be 4.9℃ with gusts up to 10.1m/s. At noon, it will rise to 5.5℃ with gusts of 13.7m/s. By 3:00 PM, the temperature will return to 3.2℃, but gusts are expected to reach 15.1m/s. During this period, the wind chill factor will likely push the apparent temperature well below freezing. A quick-drying wool or synthetic base layer, a fleece mid-layer, and a windproof/waterproof shell are essential. Additionally, carry a lightweight down or synthetic insulation layer for stops or sudden drops in temperature.

Ground conditions show no snow cover and no precipitation, meaning primarily exposed rock and dry terrain. However, some areas may be damp due to daytime temperatures. Particular caution is advised on the fragile volcanic scree above 9th station, where strong afternoon winds can cause loss of balance and dislodge loose rocks. Crampons or microspikes are not required, but full rain gear is mandatory.

As identified by the automatic risk assessment, a sharp temperature drop of 8℃ is expected within the forecast period. Summit temperatures will fall to -0.3℃ by 6:00 PM, further dropping to around -3℃ overnight, with wind chills potentially below -6℃. The combination of strong winds and low temperatures significantly increases the risk of hypothermia. An early turnaround is advisable even for daytime activities. Nighttime travel is strongly discouraged due to extreme danger. The risk of lightning is low.