Upvote:2
places which are cold and covered with snow but with a good weather to have a blast
Very very tricky. September is within the monsoon period and I don't think you will escape rain even in the hill stations. Snow will be highly improbable unless you decide to venture towards higher altitudes in the Himalayas.
The best option I can think of is Ladakh, if you want to explore the unexplored wilderness. It isn't your typical holiday place, but is sincerely a very nice place to go.