There is a Japanese proverb that states only a fool climbs Mount Fuji twice. And real fool climbs the mountain unprepared. Do your homework before ascending the mountain.

Despite the fact that the mountain rises 12,389 feet or 3,776 meters (how in the world do they know this for sure?), the climb is relatively easy. However, the final stages do get steep, so be prepared for a workout. There are chains along the path for support.

During peak climbing times — July and August comprise the “official” season — the paths are packed with people of all ages. Comfortable walking shoes are the best choice for the climb. Expect thin air as you climb. If you get dizzy or sick from altitude sickness, stop. Do not push yourself just to prove a point. The mountain will be there next time.

Before your climb make sure you have sturdy shoes, rain clothes, flashlights and batteries (especially if climbing at night), sunscreen and sunglasses, and, yes, toilet paper. It can get cold even in the hottest of summer. The height of the mountain means chilly weather year-round. Temperatures can drop to a freezing 5 degrees C in the summer. That’s really cold. Be prepared. If you wish, bring a walking stick along, or purchase one at the fifth station. You can get stamps along the route to commemorate your climb.

Take frequent breaks and bring water. Higher altitudes require more water, and you want to have plenty on hand. While there are food stations along the way, it doesn’t hurt to have something to eat with you.

If there is a worst-possible time (other than off-season) to climb the mountain, it would be Obon week in mid-August. This Buddhist holiday translates to long lines on the climbing trail. Great for people-watching, frustrating if you want to get to the top in time for sunrise. At the end of the climbing season, the Japanese celebrate the Fire Festival of Yoshida, a major festival.

If you climb out of season (which is illegal), remember that many of the services are closed, though fifth-station businesses remain open year-round and some huts on the trail might be open. Expect freezing temperatures and snow. Out-of-season climbs are very dangerous.

Resources:

Mount Fuji at WikiTravel
Getting to the top in Japan – Japan Times (Registration Required)