Snow falls sporadically on the central valleys and the days are crisp. In Thimphu and Paro, winters are surprisingly mild with only a few snow falls each year. The skies above the high mountain passes are mostly clear in winter and visitors are able to view the entire Himalayan range. Spring is rhododendron season in Bhutan. The mountain-sides all over the country are ablaze in shades of red and orange.
Days are warm but nights are still cold.
As the monsoon rises from the Bay of Bengal, spring turns to summer and three months of heavy monsoon rains. The rains come mostly in the afternoons but landslides and weather-related delays are most common during the summer monsoon. In late September the rains slow and autumn begins. Arguably the loveliest time of the year in Bhutan, autumn brings clear skies and warm days. Spotting unusual fauna in Bhutan is almost obligatory.