Yes, December is a great month to visit Manali as the entire Pir Pranjal range is covered with sparkling white snow and tourism is on its notch. The temperature ranges between 17 to 2 degrees Celsius and the trails of pines and deodar enhance the beauty of the region. Bhuntar is the nearest airport to Manali and is located at a distance of 50 km from Manali on NH21. Kullu is 10 km from Bhuntar. There are daily flights to Bhuntar from Delhi; and from the airport, you may take a cab or rent a car to reach Manali.