Istanbul is a year-round city, but spring and autumn give you warm days, cooler nights and far fewer queues.
April and May are the sweet spot: 15 to 22°C, tulips in the parks and long daylight. Expect some rain in March.
Hot and humid at 28 to 32°C, with the biggest crowds at the main sights. Good for Bosphorus evenings and Princes’ Islands day trips.
Warm seas, golden light and shorter queues. September and October are the best months for walking the city.
Cold, grey and often wet, with occasional snow. Hotel prices drop and museums are quiet; pack a proper coat.
Go in April, May, September or October for the best balance of weather and crowds. If you only have summer, start sightseeing early and use the afternoons for ferries and hammams.
See the top things to do in Istanbul, how to get there and where to stay. For the whole country, read the best time to visit Turkey.