Off-season, winter conditions & true winter ascents; the difference

Not all winter climbing on Mt Fuji is a true winter ascent. In mountaineering ‘winter’ has a specific meaning, and this applies just as much to Mt Fuji as it does anywhere else. What some people are calling climbing Mt Fuji in winter is incorrect, and the difference on the mountain itself is huge.

True winter ascents of Mt Fuji are quite rare, as conditions are very cold, winds are very high and days are short – there is a reason we are the only ones who do it. In this time it is almost exclusively serious climbers who are up there, and many turn back. No roads are open, the buildings frozen shut, and temperatures never rise above about -5c even in town.

Climbing Mt Fuji in true winter requires a strategy to offset the difficult conditions, which when done right makes for a world class ascent. We see climbers every year who have been to the Himalayas, who consider a well executed ascent of Mt Fuji a serious accomplishment.

True winter climbing is between December and March in the broadest term, and between Mid-December and the end of February in the most accepted. This is when Mt Fuji is in its coldest condition, defined by the overlap of astronomical and meteorological definitions. True winter ascents are not taken lightly in climbing circles, and to claim one when it’s not discredits a climber as even some of the greats have found out.

Off-season can mean almost anything outside of when the mountain is not totally open, including right up to the last days of June. Many off-season ascents still have snow on sections but have many people up working on the mountain, and the road can be open to 2500m.

Between real winter ascents and off-season is a window we call ‘winter conditions’ which is when the climbing is still the full winter style but conditions have eased. This may not include Japans Golden Week holiday, when some facilities on the mountain are open, but stretch into mid-April in years that are cold.