Hi there,
Austria tourism peak season is in the winter and summer, but there really isn't a bad time to visit. There's always something to see or do on Austria trips, regardless of the month, and as far as
Austrian festivals and events are concerned, they are in good supply throughout the year.
Should you visit Salzburg when heading to Austria, do take time out to visit Mozarts Geburtshaus (Mozart's Birthplace). Now a museum, it houses Mozart's childhood concert violin, his viola, his clavier (keyboard), and a pianoforte.