Leh is effectively a summer destination. The tourist season runs from late May to mid-October, when the mountain roads are open and the weather allows outdoor activities. Outside this window, both the Manali-Leh and Srinagar-Leh highways close under snow, leaving flying as the only option.
June to August is peak season. Days are long and warm — 20–25°C in town — and virtually all restaurants, guesthouses, and activities are running. The Hemis Festival usually falls in late June, drawing large crowds. Book accommodation well in advance.
September and October are excellent months: the festival crowds have gone, the skies are deep blue, and the landscape turns golden. The Markha Valley and Zanskar treks are at their best in September. October gets cold at night (0°C and below) but days remain clear.
November to May is cold and mostly closed. The high passes are buried under snow and most businesses shut. A small number of guesthouses and restaurants stay open for the few visitors who fly in, and the winter landscape of Leh — snow on the peaks, frozen river crossings in Zanskar — is genuinely spectacular for those prepared for it. The Chadar Trek on the frozen Zanskar River runs in January and February.
The altitude means UV radiation is intense throughout the year. Sunscreen, sunglasses, and lip protection are essential even in cooler months.