For most resorts, the ski and snowboard season in Japan generally starts around mid-December and goes through until around early April. Opening of course depends on the level of snow that accumulates at a particular resort, and some resorts do actually open as early as late October ("early skiing") and can continue to operate until mid-May (for "spring skiing"), usually with the help of snowmaking machines.

Tenjindaira in Gunma is usually on of the first resorts to open for the year with natural snow with its lifts usually firing up by Culture Day in early December.  Other early resorts to open can be found in Hokkaido and Nagano.  Keep an eye on the Daily Reports Center as well as the Forums for the latest information.

The strangest season undoubtedly goes to Gassan in Yamagata Prefecture. Due to inaccessibility because of heavy snowfall, the season doesn’t usually start until April and continues until late July.  Another interesting season is at a resort in Niigata called Okutadami.  The road that approaches the resort gets blocked with snow in the peak season meaning that the resort opens for a month or two in December and January and then closes for a few months before re-opening in mid-March.

The peak of the season is from mid-January until the end of February.  Images of slopes packed full of people with almost nowhere to ski without bumping into other people are outdated.  While the weekends and national holidays at popular resorts can get extremely busy, on weekdays you will often find slopes very uncrowded - even at popular resorts.

The busiest weekend is the three-day weekend in mid-February when most resorts are at their busiest. Weekdays - even in the middle of the season - do not get too busy, even at the most popular resorts, where you can sometimes find yourself nearly alone on the slopes. If it’s possible to get a Friday or Monday off to avoid leaving, or more importantly returning during rush hour traffic, that would also be advised. On Sunday evenings after a good snow weekend, only the dedicated (or mad!) should brave the expressways at peak times.