Kaleiçi (Old Town) in January

April through June gives you the sweet spot—warm enough for harbor walks but cool enough that the cobblestones won't burn through your shoes. May particularly shines, with temperatures around 22°C and hotel prices still reasonable before summer crowds arrive. September through November offers similar conditions plus the bonus of fewer tour groups. Summer means sweltering heat that makes afternoon exploration miserable, though the harbor breeze provides some relief. Winter brings rain and closed restaurants, but also rock-bottom hotel prices and a moody atmosphere that photographers love. The Christmas market in December adds unexpected charm, though many businesses shut down from January through March.