Darjeeling is the most popular hill station in the eastern Himalayan region in India, having an altitude of about 6,500 feet above the sea level. The neighboring hilly state Sikkim's capital Gangtok is another popular hill station after Darjeeling.
On a personal note,I would suggest Darjeeling over Gangtok, mainly because of the natural beauty and magnificent view of Kanchendzongha ranges that it offers. The colorful life in a hill station can be enjoyed more in Darjeeling. It also offers excellent options for food.
The minimum temperature starts dropping from 13°C in September to 6°C in November, while the maximum temperature ranges from 18.3°C to 12.8°C during this period. The winter starts in December although it's not usually unpleasantly cold around this time. The temperature ranges from 2.4°C to 9.6°C in December.
The best way to travel between Darjeeling and Gangtok is by private taxi which takes 1.5 to 2 hours. The journey is full of beautiful landscapes. Most of the roads are in good condition and one can stop midway to enjoy the scenic beauty
The two predominant religions are Hinduism and Vajrayana Buddhism. Dashain, Tihar, Buddha Jayanti, Christmas, Holi, Ram Navami, etc. are the main festivals. Besides, the diverse ethnic populace of the town also celebrates several local festivals.