Wittenberg is a year-round destination, though summer (May–September) is the most comfortable time to visit. The town is busiest around 31 October — Reformation Day — when events mark the anniversary of Luther's 95 Theses. The 500th anniversary in 2017 brought large crowds; in ordinary years the celebration is more modest but still atmospheric.
Spring and early autumn are arguably the best times: pleasant weather, smaller crowds, and good light for the historic streetscapes. Winter is quiet and cold, but the museums are open throughout the year and the lack of tourists gives the town an appealing stillness.