The summer trekking season runs from late June to mid-October. July and August are the warmest months, with daytime temperatures in the valley reaching 20–25°C and nights cool but manageable at around 5–10°C. These months also see the most visitors, though Zanskar remains far less busy than popular Ladakh destinations like the Nubra Valley.
The road over the Pensi La from Kargil typically opens in late June and closes again in late October when snow returns. Before and after these dates, access is by helicopter from Leh (occasional, weather-dependent) or on foot over the passes.
The Chadar Trek — walking the frozen Zanskar River — runs in January and February, when the river gorge is solidly frozen. This is a completely different experience: extreme cold (-15 to -30°C at night), spectacular winter light, and a genuine sense of the hardship the route represents for Zanskar's villagers. The ice is forming less reliably in recent years, so check conditions carefully before committing to dates.
The monastery festivals — Karsha Gustor in summer, Sani Tsechu — vary in date each year according to the Tibetan lunar calendar. Asking in Leh or contacting Padum guesthouses for the current year's festival dates is worthwhile if you want to coincide with one.