The travel industry's best-kept non-secret is that 'peak season' mostly measures crowd psychology, not destination quality. The Mediterranean in late September is warmer than in June, emptier than in August, and 40% cheaper than either. The people who know this simply never travel in peak months again.

Shoulder season, the six-to-eight-week bands flanking high season, is the arbitrage. Weather typically 90% as good, crowds down 50 to 70%, and pricing that reflects hotel occupancy panic rather than demand euphoria.