雨上がり脆い火山礫に注意。稜線風強く冷え込む

As of 7 AM, Rishiri-zan summit is experiencing light rain with a temperature of -1.2°C, feeling like -6.9°C due to the strong wind. A significant temperature difference of about 9.4°C exists between the summit and the base. Although the forecast for today indicates clearing skies from cloudy conditions, summit temperatures will only rise to around 1 to 2°C. Wind speeds will average 6 m/s, with gusts reaching up to 15 m/s, keeping the perceived temperature around -5°C throughout the day.

Under these conditions, the ground will be wet and muddy from the rain. The fragile volcanic scree found above the 9th station on routes like the Oshidomari Course will be particularly slippery. Extreme caution is advised to prevent slips and falls. Wear waterproof and windproof outer shells, ensuring your base and mid-layers provide adequate insulation. Gloves and a hat are essential.

The risk of hypothermia remains high all day, especially if wet from rain, as it can rapidly deplete your energy. Plan for an early start and avoid overly ambitious itineraries. Crampons or microspikes are not necessary, but waterproof hiking boots are crucial. Temperatures will drop below freezing again after sunset, with perceived temperatures nearing -8°C. Avoid any activity after dark.