Bhutan has four seasons in a year; winter from December until February, spring from March to May, summer from June to August and autumn from September until November. Though it is possible to visit Bhutan throughout the year, the best seasons to visit Bhutan are in spring and autumn. During these months of the year, Bhutan has not only favorable and pleasant climatic conditions but also has lot of on-going festivals and events within the country.
Spring and autumn are also the peak season amongst the tourist and unless the tour reservation is made 2 months before the departure date to Bhutan, it is usually very difficult to visit Bhutan within short notice of your reservations. This is because of limited seat capacity in Druk-Air, the only airline that flies in and out of Bhutan and constraint of accommodation facilities and other infrastructures within the country.