Mt. Daisetsu is not an independent mountain. It is the name for range of mountains located in the center of Hokkaido.
Mt. Daisetsu is well known as the place you can enjoy brilliant autumn color of leaves first in Japan.
It was on the 21st, September when I climbed Mt. Kurodake(one of the mountains in Mt. Daisetsu National Park) with the tourists I attended. It was only around the summit that was tinted at that time.
However, the following day, the local news said that there was a snowfall at the top of the mountain, and actually, it got much colder than the previous day.
By this time, Mt. Daisetsu’s autumn color must have much progressed, since flamboyant colors of leaves are created by the big difference of temperatures of daytime and nighttime.