Lefkada has the standard Greek-summer rhythm. June and September are the best months — warm seas, hot but not blistering days, and the high-season crowds either gathering or thinning. July and August are very hot (often 35°C+) and the west-coast beaches and Lefkada Town can be uncomfortably busy.
May is pleasant but the sea is still cold; October brings the first rains. The island shuts down substantially from November to mid-April.
The International Folklore Festival in Lefkada Town in late August is a long-running event drawing dance troupes from around the world. Smaller summer panigyria (saint's-day festivals) in the villages — Karya, Englouvi, Vafkeri — are a better way to see traditional Lefkada music and dancing.