I read several web site and reached here to ask some questions.
How cold there? Do I need to bring full winter jacket? Which website can we see the temperature there?
And also which website will be useful to check the weather before we go?
It’s 3.6 degrees celsius on average at the summit. It can be 0 degrees celsius depending on situations.
Most people have some parkers or sweat shirts. You should have a rain jacket because the weather will change suddenly.
This website will be useful. http://www.fujisan-climb.jp/en/weather/index.html