The weather in Istanbul in September is hot. The average temperatures are between 21°C and 25°C.
You can expect about 3 to 8 days of rain in Istanbul during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Istanbul in September 2025.
If you’re planning to visit Istanbul in the near future, we highly recommend that you review the 14 day weather forecast for Istanbul before you arrive.
Temperatures
25° / 21°
Rainy Days
3
Snowy Days
0
Dry Days
27
Rainfall
63
mm
Sun Hours
11.1
Hrs
