The best time for trekking Auden's Col trek is from May(from 4th week) to September(barring monsoon period). During the spring season(in May & June month), wildflowers, including pink rhododendrons, Bhrama Kamal bloom in Gangotri valley in Uttarakhand. The clear skies and stable weather is the major attraction of the trek.
The autumn month of September is famous for its soothing climate and favorable temperatures. The Autumn month is good for the night or dawn/dusk photography. The monsoon and the winters are generally avoided because of the risks and the challenges posed by the Gangotri group of mountains.