Istanbul Weather in September
Istanbul in September averages 25°C (77°F) during the day and 19°C (66°F) at night. Some rainfall is typical for this time of year.
Rainfall in Istanbul in September
The climate data from previous years indicates about 6 days of rain, averaging 51 mm (2 in) for the month. The rain this month typically falls in concentrated bursts rather than all-day showers. Expect a few heavier spells rather than constant grey skies.
Temperature in Istanbul in September
If you're visiting Istanbul in September, expect excellent temperatures with highs of 25°C (77°F) and overnight lows of 19°C (66°F). The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. With overnight lows of 19°C (66°F), evenings can feel noticeably cooler than the daytime. An extra layer is a good idea, though the cool air makes for a good night's sleep.
Sunshine in Istanbul in September
The month enjoys around 235 hours of sunshine, creating mostly sunny days with good weather conditions.
Average water temperature in September
The water temperature is 23°C (73°F), which most people find very comfortable. A good month for swimming and water sports.So this is a great month to visit if you prefer dry days with pleasant temperatures.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Turkey, check out our Istanbul's climate page.
Istanbul Temperature in September
Min Temperature
19°C (66°F)
Max Temperature
25°C (77°F)
Water Temperature
23°C (73°F)
Chance of Rain
20%
Precipitation
51 mm (2 in)
Rainy days
6 days
Sunshine
235 hours
Percentage Sunshine
65%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Istanbul typically drop from around 27°C (81°F) at the start of September to approximately 23°C (73°F) by the end. Nights are pleasant, with lows typically ranging from 16°C (61°F) to 20°C (68°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Istanbul in September
Browse day-by-day weather records for Istanbul spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Istanbul historical weather extremes in September
Our historical data for Istanbul spans 1976 to 2025, revealing these weather extremes.
- On September 20, 2017, temperatures climbed to 35°C (95°F), marking the warmest September day on record.
- The lowest daytime temperature in September was 14°C (57°F), recorded on September 28, 1977.
- Nighttime temperatures dropped to 10°C (50°F) on September 27, 1977, marking the coldest September night on record.
Best Places in Turkey in September
Find out more about the weather in Turkey and which places have the best travel conditions in this month. See all of Turkey in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Istanbul in September
Warm but pleasant conditions in Istanbul in September. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. Wet weather is likely, so pack waterproof gear for multiple rainy days. With water temperatures around 23°C (73°F), swimming conditions are excellent. Pack your swimsuit, goggles, and maybe some water shoes. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in Istanbul in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Turkey, check out our Istanbul's climate page.
Temperature Rainfall Sunshine Water Temp
See the full Istanbul climate overview or explore weather in Turkey.
