Shangri-La is at altitude and the weather is more mountain than south China. Summer (June–September) has the best temperatures — 15–22°C during the day — and the wildflowers on the grasslands are at their peak. It is also the wettest time; expect afternoon rain, particularly in July and August, and occasional roadblocks from landslides on the road north.
Spring and autumn are reliable shoulder seasons. May has wildflowers without the summer crowds; October has clear, dry weather and the autumn colours on the slopes; both are good times for hiking.
Winter (December–February) is cold — below freezing most nights, and well below by day in January — but it is the season for black-necked cranes at Napa Lake and the views are at their clearest. Snow can close the road over the passes to Deqin for days at a time; check before you commit to a route north.
The Horse Racing Festival, usually in late May or early June, is the major local event — Tibetan riders from across the region come to compete on the grassland south of town.