All season are best to visit Bhutan in any time of year. Bhutan shows beautiful faces as in all season. In fact, the four seasons (Winter, Spring, Summer & Autumn) in Bhutan has it’s own characters to beautify the Land of Thunder Dragon.
Never the less, the governing authority, Tourism Council of Bhutan has segregated the 12 months into two seasons for visitors, as:
Peak Season (High Tourist Season):
March, April, May, September, October, and November.
Off-peak Season (Low Tourist Season):
January, February, June, July, August, December
Additional season information:
April, May & June are flowering season where you can enjoy the breathtaking beauty of about 46 species of rhododendrons.
September, October & November is the festival season. This is the time if you want to witness unique festivals of Bhutan.