When is the best season for via ferratas?

Season start: late spring.
Once snow is gone and operators have opened the route, climbing begins. In lower areas, this can be in May. Higher regions may wait until June or later, depending on remaining old snow on the wall.

End of season: first snow.
Once snow falls at altitude, conditions become critical. Ice, snow, wet surfaces make footholds slippery, ropes hard to control, orientation difficult. Many routes close in October. Earlier if early winter arrives.

Winter: not recommended.
Via ferratas in snow or ice are dangerous, not intended. Ropes may be frozen, footholds hidden. Climbing gear not designed for these conditions, especially fall arresters unreliable in cold. Only specially designated winter routes (rare) or experienced alpinists with full protection attempt winter climbs.

Exceptions in the south.
A few via ferratas in southern Switzerland or low altitude can theoretically be climbed year-round. Still, without current information on conditions, closures, or ice, do not start.