Bojnice is a year-round destination but is busiest in summer, when the castle, zoo, and thermal baths all operate full hours. The International Festival of Ghosts and Spirits at the castle, held in late April or early May, is the event most visitors come specifically to see — theatrical performances, costumed figures, and atmospheric lighting make it one of the most distinctive castle festivals in Slovakia.
Winter visits are quieter but the castle stays open, and the thermal baths are especially pleasant when it is cold outside. Spring and early autumn offer the best combination of manageable crowds and good weather for outdoor sightseeing.