An estimated 8,000 to 12,000 people illegally enter Mount Fuji's climbing trails during the closed season each year, despite government warnings and barriers, according to data analysis by Yomiuri Shimbun and location intelligence firm Location AI.
Mount Fuji's four climbing routes – Fujinomiya, Subashiri, Gotemba on the Shizuoka side and Yoshida on the Yamanashi side – are only open from early July to September 10 each year.
Prefectural governments have installed signs and barriers between the fifth and sixth stations, but climbers continue to ignore them. Between 2019 and 2025, 79 people have been involved in mountain accidents during the closed season, with 19 deaths.
The analysis, based on mobile phone location data, found that the Fujinomiya route – which allows car access to the fifth station and offers the shortest path to the summit – accounts for about half of the illegal climbs. Climbers aged 50 and above make up more than half of the total.
The data does not include foreign tourists, who account for 20 to 50 percent of climbers during the open season. The actual number of illegal climbs is likely higher, as foreign climbers have been involved in accidents during the closed season.
A local official said the figures were higher than expected and called for more effective countermeasures.
