What is the annual average temperature at the summit of Mount Fuji? What is the approximate temperature at the summit during summer climbing season?

Okay, regarding the temperature at the summit of Mount Fuji, I'll explain it, hoping it helps you.

Mount Fuji Summit Temperature: Annual Average & Summer Climbing Reference

If you plan to climb Mount Fuji, understanding the temperature at the summit is crucial because it's completely different from the "summer" you might imagine.

1. What is the average annual temperature at the summit?

Simply put, extremely cold.

The average annual temperature at Mount Fuji's summit is approximately -6.2°C.

To put that in perspective, think of it as a huge, constantly running "giant natural freezer". Even during the hottest month in the lowlands, August, the average summit temperature is only about 6°C. For this reason, the summit is mostly covered in snow year-round, and climbing is only officially open from July to early September.

2. What is the temperature like at the summit during summer climbing season?

This is the biggest concern for climbers. While summer is the Mount Fuji climbing season, the word "summer" has almost no meaning at the summit.

One-sentence summary: Even at the peak of summer, the summit temperature is comparable to the depths of winter in lowland areas.

Specifically:

Daytime (Clear Weather): If you're lucky and have clear, sunny weather, the sun's direct rays might make it feel slightly warmer. Daytime temperatures usually range between 5°C and 8°C. However, this is just the air temperature. The summit has extremely strong winds and intense ultraviolet radiation, so you might feel scorched by the sun while simultaneously freezing from the wind.
Nighttime & Early Morning (Sunrise Viewing): This is the real challenge! Most climbers start ascending around midnight to reach the summit for sunrise (Goraiko) between 3-5 AM. Temperatures at this time plummet to around 0°C, or even below freezing.
- It feels even colder! The summit has almost no shelter, and winds are often very strong. With an air temperature around 0°C, a strong gust can instantly make the wind chill feel like -5°C to -10°C. That's why many people feel absolutely freezing or frozen to the bone while waiting for sunrise at the summit.

Simple Tips for Climbers

Don't be fooled by the weather at the base! You might be wearing a T-shirt at the 5th Station (the starting point around 2300m) feeling fine. But remember a simple physical rule: Temperature decreases by approximately 0.6°C for every 100 meters of elevation gain. From the 5th Station to the summit (3776m), the altitude gain is nearly 1500m. This elevation difference alone will cause the temperature to drop by about 9°C.
You absolutely must bring adequate cold-weather gear! Take this seriously. Employ the "onion layering method" (wearing multiple thin layers).
- Base Layer: Moisture-wicking thermal underwear.
- Mid Layer: Insulating layer, like a fleece jacket or thin down jacket.
- Outer Layer: Windproof and waterproof hard shell jacket.
- Other: A warm hat (covering your ears), gloves, and a scarf or buff are absolutely essential, as extremities lose heat fastest.

Hope this information helps! Have a safe and successful climb, and enjoy the beautiful sunrise!