May through September is the best time to visit Eger. The weather is warm to hot (25–35°C in July and August), the outdoor restaurants and wine cellars are in full swing, and the castle and gardens are at their most attractive. The Eger Wine Festival in July draws large crowds but is one of the best events in the Hungarian festival calendar.
Spring (April–May) is lovely — the blossoms are out in the Archbishop's Garden, the weather is mild, and crowds are manageable. Autumn (September–October) is harvest season, when the wine region is particularly active and the colours in the Bükk hills are beautiful.
Winter is cold (temperatures often below freezing in January) but Eger is worth visiting in December for the Christmas market around Dobó Square, and the thermal baths are particularly inviting when the air is cold.