When is the best time of year to trek in Bhutan?

There are two main trekking seasons in Bhutan. Spring season starts in March and carries on to the end of May. Autumn season starts in mid September and carries on to the end of November.
The most popular month to trek in Bhutan is October followed by November then April.

The daily weather pattern in Spring tends to have clear mornings with views of the mountains followed by cumulus clouds build up during the afternoon followed by clear skies at night and into the next morning. However of course one can get a cyclonic system causing stormy weather with precipitation at any time of year….

In Spring you will see flowers in bloom especially rhododendron. One can see rhododendron flowers from mid-March to mid-May depending on altitude and aspect of slope.

The main advantage of Autumn is the higher chance of getting clear skies that is best for mountain photography. The monsoon rains during June to September clears out the dust and pollution from the air. After the monsoon it is normal to get a blocking high pressure sitting over the Himalaya resulting in sunny weather and blue skies however the timing of this depends year to year.

For some years the monsoonal influence continues into the end of September and other years it winds down in early September. In Autumn it is possible to get sunny conditions with blue skies throughout the day whereas this is less likely in spring when cloud normally builds up in afternoon.

Winter is a superb time to visit Bhutan on a Cultural Tour as the weather is often usually sunny and stable as well as having far fewer other visitors around in December and January. The temperature would be too cold for most treks.