午前は穏やか。午後は急激な寒さと霧雨に警戒

Mount Meakan summit currently enjoys fair weather with a temperature of 9.7°C and a light wind of 0.96m/s, offering calm conditions. The temperature difference from the base is approximately 5°C. This favorable weather is expected to continue until around 9 AM, making the Onneto Course dry and suitable for ascent during this period.

However, conditions will change rapidly around noon. Light rain is forecast to begin by 12 PM with temperatures at 8.8°C. By 3 PM, the temperature will plummet to 0.4°C, accompanied by winds of 4.62m/s and gusts up to 13.3m/s. With the combination of light rain and strong winds, the wind chill factor will drop significantly to around minus 7°C. The scree slopes of Mount Meakan will become slick and hazardous due to the rain, increasing the risk of falls.

A rapid temperature drop of 20°C is expected during the forecast period. Be prepared for sudden changes by carrying extra insulating layers such as a warm fleece or light down jacket, in addition to waterproof and breathable rain gear. During the afternoon's deteriorating weather, strong northerly winds could cause sulfur gas from the fumaroles to accumulate along the crater rim and leeward trails, increasing the risk of acute sulfur gas poisoning. Avoid prolonged stays around the crater lakes. It is crucial to begin your descent no later than noon.

By 6 PM, temperatures will fall to minus 3.3°C and further to minus 6°C overnight. Climbing in the afternoon is strongly discouraged due to the extremely high risk of hypothermia.