What is the weather like and what to wear during the Spring Festival in Japan?

Both Osaka and Tokyo are not very cold, and there is no wind.

Recently it has been 3-7 degrees above zero. It will be a bit cold in the morning, but a cotton-padded jacket is enough. I think underpants are enough for one day. Anyway, I wear this all the time when I go to Japan in winter. It’s not cold. If you are not very resistant to freezing, just wear more clothes.