İstanbul Weather in September
What's the weather like in İstanbul (Istanbul) in September 2025?
The climate in İstanbul during September can be summarized as warm and reasonably dry.
September is in the fall / autumn in İstanbul and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 24°C (75°F), whilst at night 16°C (60°F) is normal.
| Daytime temperature | 24.1°C 75.4°F |
|---|---|
| Nightly temperature | 15.5°C 59.9°F |
| Average temperature | 19.8°C 67.6°F |
| Daily sunshine | 9.7 hrs |
| Avg rainfall | 43 mm 1.7 ins |
| Rainy days | 6 days |
| Sea temperature | 22.5°C 72.6°F |
| Humidity | 74% |
| Windspeed | 10.8kph 7 mph |
On average September is the 5th driest month of the year in İstanbul with around 43mm 1.7 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 6 days, although this may vary considerably.
On the flip side this corresponds to an average of 9.7 hours of sunshine per day.
September temperatures in İstanbul
September rainfall
September hourly sunshine
The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in İstanbul in September 2025.
Other monthly averages
Best places to visit in September
İstanbul weather stats
| Hottest month: | August | 26.8°C 80.2°F |
|---|---|---|
| Driest month: | July | 25mm 1ins |
| Sunniest month: | July | 12.7hrs |
| Coldest month: | January | 8°C 46.4°F |
| Wettest month: | December | 126mm 5ins |
© Google
Locations nearby
Top Turkey locations
- Alanya
- Ankara
- Antalya
- Belek
- Bodrum
- Çeşme
- Dalaman
- Didim
- Fethiye
- İstanbul
- İzmir
- Kemer
- Kuşadası
- Marmaris
- Side