The rangers of the Jigokudani Snow Monkey Park have changed the Park opening times from 8:30 to 17:00 to 9:00 to 16:00. This because of the shorter days.
The monkeys have a habit of coming down from their sleeping place in the mountains as soon as it the sunlight hits, and go back up the mountains to find a good tree to sleep in when it get dark. In the winter months, the days are shorter than in the warmer seasons, and this makes the monkeys come down later and leave the park earlier than they would in summer or autumn.
So if you want to visit the park, please come between 9:00 and 16:00 for the coming months! See the Destination page for more snow monkey info!