9th Arrondissement (Opéra) in December

April through June brings perfect weather and manageable crowds. The opera season runs strong, department stores launch spring collections, and café terraces reopen. Hotel rates climb but remain reasonable compared to summer peaks. September and October offer the sweet spot — warm days, crisp evenings, and locals back from August holidays. The Nuit Blanche art festival in early October turns the neighborhood into an open-air gallery. Avoid July and August unless you enjoy fighting tour groups at every turn. Many locals flee the city, leaving restaurants understaffed and streets overrun with visitors. December brings Christmas markets and holiday window displays, but expect crowds and premium prices.