How is Mt.Fuji weather
The weather in mountain can be changed very easily and quickly.
The temperature difference between station 5 nd the summit is more than 20 C.
Suddenly start to rain with thunder storm.
You better check the weather condition before going there to enjoy the trekking day.
Average temperature is about 5°, however while you are waiting for sun rise, it can be freezing point.
You better prepare enough equipment like warm jacket and rain wear(separated type is recommended)