残雪と低い視界。慎重な行動が求められる

Mt. Yari summit is under thin clouds with a temperature of 4.3°C, feeling like 1.9°C. Winds are calm, but visibility is poor, below 1km. Snow depth is 64cm, indicating it is still the remaining snow season. Note the 10.3°C temperature difference from the base, highlighting the impact of elevation on conditions.

Throughout the day, thin clouds are expected to persist, with temperatures rising to 6.9°C after 9 AM. Wind speeds will remain low, around 1m/s, maintaining calm conditions. Although the chance of precipitation increases in the afternoon, the forecast is for 0mm of rain, suggesting a low risk of thunderstorms.

At this time of year, extensive snowfields remain on the Yarisawa route. While the surface will soften with daytime warming, it will be firm in the mornings and evenings. Crampons and an ice axe are essential gear. Particularly on the rock sections and ladders near the summit, where rock and snow coexist, footing will be slippery, demanding careful movement. With persistently low visibility, meticulous attention to route finding is crucial. The effective temperature at the summit will remain low throughout the day, so a three-layer insulation system—base, mid, and outer shell—is mandatory. Carry rain gear to prevent hypothermia from getting wet. While travel is possible, navigating remaining snow in poor visibility requires skill and experience. Temperatures will drop to around 2°C after sunset, causing the remaining snow to refreeze.