Hi, last year when I was there in November, the weathe is not very cold but it was colder when it rained the second day. T-shirts is enough it it sunny, but you'd better bring a coat for rainy days. Southern Part of Tanwan is warmer than the northern part.

For the trains to Alishan, I heard it was damaged but was reopened later, but I'm not sure if the typhoon days before has affected it.