Ravenna is best visited in spring (April–May) and early autumn (September–October), when the weather is mild and the monument queues are manageable. Summer brings heat and larger crowds, particularly at the peak tourist season in July and August when the Adriatic beach resorts nearby are at full capacity. The monuments stay open year-round, however, and winter visits — when the city is quiet and the mosaics can be contemplated without competition — have their own appeal.
The Ravenna Festival, a major classical music event, runs in June and July, bringing opera and orchestral concerts to historic venues including the basilicas. This is one of the few occasions when you can hear music inside the mosaic-lined churches, and the combination of setting and performance is exceptional. Book accommodation well in advance if visiting during the festival.