Monsoon rains and leeches put an end to most treks, although high-altitude flowers are at their peak.
Bhutan has seasonal tariffs so, along with fewer tourists, there are good savings to be made by travelling outside the high season.
The weather is still pleasant, though it can be cold in December and January.
The weather is ideal in spring and autumn. Book flights well in advance; accommodation options can fill up.
Himalayan views are best in October, while rhododendron blooms peak in March and April.