The shrine is open year-round, but the experience varies enormously by season. The pilgrimage is most pleasant from March to October when the weather on the mountain is mild. April and October–November correspond to Navratri, the two annual nine-night festivals of the goddess — these are the busiest periods, with single-day pilgrim counts that can exceed 30,000 and queue waits of many hours for darshan.
Summer (May–June) is hot at the base in Katra (over 35°C) but cool at the cave; the climb is sweat-drenched but doable. July–August brings the monsoon, with landslides occasionally closing parts of the trail. December–February brings snow on the upper sections and below-freezing nights — fewer pilgrims, but you may not be able to reach Bhairav Nath at all.
The busiest days are weekends and the new-moon days; pick a weekday in shoulder season for the shortest queues.