Istanbul weather in September
September is one of the best months to visit Istanbul: highs of 25°C (77°F) and about 54 mm (2.1 in) of rain on average. Nights average 19°C (66°F) and cloud cover 46% (NASA POWER, 2001–2025 averages). The sea averages 24°C (76°F). It is the 6th wettest month of the year and the 4th warmest. Compared with August, it is cooler and wetter; October brings highs of 20°C (67°F) and 70 mm (2.8 in) of rain.
Figures are long-term averages for Istanbul, the largest city in Istanbul. See below for other places.
Is September a good time to visit Istanbul?
best month Weather score 82/100.
Yes. September is one of the best months for weather in Istanbul.
Does it rain a lot in Istanbul in September?
No, it is usually dry: about 54 mm (2.1 in) falls in an average September. It is the 6th wettest month of the year.
How warm is Istanbul in September?
Days average 25°C (77°F) and nights 19°C (66°F).
Istanbul weather by month
| Month | High | Low | Rain | Cloud | Sea | Weather |
|---|---|---|---|---|---|---|
| January | 8°C (47°F) | 4°C (38°F) | 79 mm | 76% | 10°C (50°F) | least pleasant |
| February | 9°C (48°F) | 4°C (39°F) | 68 mm | 75% | 9°C (48°F) | least pleasant |
| March | 12°C (53°F) | 5°C (42°F) | 53 mm | 67% | 9°C (49°F) | fair |
| April | 16°C (60°F) | 9°C (47°F) | 42 mm | 61% | 11°C (53°F) | fair |
| May | 21°C (70°F) | 14°C (57°F) | 35 mm | 55% | 15°C (59°F) | best |
| June | 26°C (79°F) | 19°C (66°F) | 36 mm | 42% | 21°C (70°F) | best |
| July | 29°C (84°F) | 21°C (71°F) | 20 mm | 28% | 25°C (78°F) | best |
| August | 29°C (84°F) | 22°C (71°F) | 22 mm | 30% | 25°C (77°F) | best |
| September | 25°C (77°F) | 19°C (66°F) | 54 mm | 46% | 24°C (76°F) | best |
| October | 20°C (67°F) | 14°C (58°F) | 70 mm | 59% | 20°C (68°F) | best |
| November | 15°C (59°F) | 10°C (49°F) | 63 mm | 68% | 16°C (61°F) | fair |
| December | 10°C (50°F) | 6°C (42°F) | 82 mm | 74% | 13°C (55°F) | least pleasant |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), sea temperature from Open-Meteo Marine. Page updated . How we rate months
Weather across Istanbul in September
Weather can differ a lot within Istanbul: coasts, hills and mountains each have their own climate.
| Place | High | Low | Rain | Weather |
|---|---|---|---|---|
| Istanbul | 25°C (77°F) | 19°C (66°F) | 54 mm | best |
| Esenyurt | 25°C (77°F) | 19°C (66°F) | 54 mm | best |
| Küçükçekmece | 25°C (77°F) | 19°C (66°F) | 54 mm | best |
| Bağcılar | 25°C (77°F) | 19°C (66°F) | 54 mm | best |
| Bahçelievler | 25°C (77°F) | 19°C (66°F) | 54 mm | best |
| Ümraniye | 25°C (76°F) | 18°C (64°F) | 56 mm | best |
| Üsküdar | 25°C (77°F) | 19°C (66°F) | 54 mm | best |
| Esenler | 25°C (77°F) | 19°C (66°F) | 54 mm | best |
| Sancaktepe | 25°C (76°F) | 18°C (64°F) | 56 mm | best |
| Sultangazi | 25°C (77°F) | 19°C (66°F) | 54 mm | best |
| Maltepe | 25°C (76°F) | 18°C (64°F) | 56 mm | best |
| Beylikdüzü | 25°C (77°F) | 19°C (66°F) | 54 mm | best |