The best times to visit Bumthang are spring (March–May) and autumn (September–November). Spring brings rhododendron blooms on the surrounding hillsides; autumn offers clear skies and the most important festival season.
Two major festivals are worth timing a visit around. The Tamshing Phala Chhoepa takes place in late September or early October (ninth lunar month), with three days of cham masked dances at Tamshing Monastery. The Jampey Lhakhang Drup in October includes the famous Mewang midnight fire ritual. Both draw large crowds of Bhutanese pilgrims and are open to foreign visitors.
Winter (December–February) is cold — Bumthang sits at around 2,600 metres — but clear and relatively uncrowded. Summer (June–August) brings the monsoon: green and dramatic landscapes, but rain can disrupt mountain road travel.