Bhutan is a small, mountainous country with altitude ranging from 160 meters to more than 7000 meters above mean sea level. In Bhutan, the climate is influenced largely by the altitude and temperatures vary accordingly with the elevation. The climate is humid and subtropical in the southern plains and foothills, temperate in the inner Himalayan valleys of the central regions, cold in the north, with year-round snow on the main Himalayan range. From late November to March, winter sets in with frost throughout most parts of the country often with multiple snowfalls. 

Bhutan's generally dry spring starts in early March and lasts until mid-April. Summer weather commences in mid-April with occasional showers and continues to late June. The summer monsoon brings rains and widespread cloudiness for almost half a year, but especially from June to late September, mostly confined to to Southern border region of Bhutan. The heavier summer rains last from late June through late September which are more monsoonal along the southwest border. 

In general, the best time to visit Bhutan is from March to May during the spring season and autumn from September to November, when temperatures are moderate and rain is a distant worry. This is also the reason why these months receive the most visitors to Bhutan in the year. During the summer, the rains can make the roads muddy as well as having occasional landslides at some stretches of road and the clouds can hide the mountain peaks too. In winter, the weather is generally good, providing clear views of the Himalayas but it's cold in the mountains and snow can fall at high altitudes blocking some passes. Summer and Winter are off-peak seasons but have it's own charm.. this makes a good traveling period for return visits to Bhutan as well as for visitors looking to pay a lower traveling fees.