Snow is no doubt one of the more interesting features in the Himalayan terrain. Where glaciers represent permanent ice, snow is temporary, falls during winter and retreats during summer. The snowline (altitude where snow starts) is very dynamic. It changes as per the seasons: fresh winter snow fall usually sets in around September and summer season (start of snow melt) starts around April.

The snowline also moves up and down during the winter itself - fresh snowfall might lower the snowline by 500 meters followed by 2 weeks of sun where the snowline retreats again 300 meters up. As usual, snow melt is more on the East / South facing slopes while the North / West facing slopes will retain fresh snow longer due to less solar exposure. Due to the dynamic nature of snow it can obviously not be marked on maps and we should follow the weather forecast to get an idea of lowering (fresh snowfall) or receding (sunny weather) of the snowline.

The snowline is very dynamic but important to plan your journey. Passes are usually "open" (free of snow) in certain months and closed during the rest of the season. 3000m+ high passes might be open May-Nov, 4000m+ passes (e.g. Dhauladar) in June-Sept, 5000m+ passes (e.g. Pir Panjal) in July-Aug. Survey of India maps usually mention the months during which marked passes are open.