The Valley of Flowers is only open from the beginning of June until the end of September as it's covered in snow the rest of the year. The best time to visit is from mid July to mid August, when the flowers are in full bloom after the first monsoon rain. If you go before July, you’ll find hardly any flowers at all. However, you will be able to see melting glaciers. After mid August, the color of the Valley changes quite dramatically from greenish to yellowish, and the flowers slowly die.