Is it suitable to visit Koyasan in winter

I'm in Osaka and very interested in the temples in Koyasan. If weather permits, I would like to visit there in Feb 11. However, is it suitable to go to Koyasan in winter? (I am worried if it will be dangerous.)

Yes, it is a great place in winter, although snow is not guaranteed. It becomes very cold, though. So if you don't like the cold, you may not want to visit in winter. Even the rooms in the temple can be very cold, although heaters are provided.

My brother and I went to Koyasan in early November one year and it snowed and was very beautiful but also very cold which we were not entirely prepared for. I think it is a lovely time to go but take proper winter clothes (we didn't and ended up leaving early because we were freezing). The temples I have stayed in there do not have great heating either so be prepared. Having said that I will also say that Koyasan is stunning under the snow. :-)

I went to Koyasan in late November last year; no snow but still quite cold, although we just needed jumpers and an overcoat and we were okay. The temple we stayed in, Ekoin, provided us with a kotatsu (heated table, very cosy) and a heater in our rooms; it was cold outside the rooms but perfectly fine inside (and in the onsen!). I even overheated while sleeping - the futon were very toasty! I saw a picture of Koyasan in the snow, it looks absolutely beautiful; so I don't see any reason not to go as long as you are well prepared for the cold and double check that your temple lodgings will provide adequate heating.