18th Arrondissement (Montmartre) in January

April through June gives you mild weather and longer days without the summer crush. The artists set up their easels in Place du Tertre by 10am, and you can actually move through the crowds. September and October bring perfect light for photos and comfortable temperatures for climbing all those stairs. The grape harvest festival happens in early October — one of the few times locals outnumber tourists. Summer means shoulder-to-shoulder crowds and prices that spike 30%. But the sun doesn't set until after 9pm, giving you magical golden hour light on the basilica steps. Winter clears out the crowds but brings gray skies and rain. The upside? You'll have those winding streets mostly to yourself, and café windows glow warm against the cold. Just dress warmly — it's always windier up on the hill.