Istanbul
Turkey
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Istanbul, Turkey

Ships along the coast of the port city of Istanbul, Turkey, with a background view of the cityscape
Ships along the coast of the port city of Istanbul, Turkey, with a background view of the cityscape
September is one of the best times to visit Istanbul at the start of the autumn season with mild temperatures and modest rainfall. The average temperatures drop from the highs of summer to the comfortable range of 16.7°C (62.1°F) to 23.9°C (75°F).
The heat tapers down with each passing day as the clouds push over the Atlantic to bring moderate rainfall of 61mm (2.4") in September. The sunshine drops to a daily 8 hours as the daylight shrinks to 12 hours.
Overall, the weather is comfortable and calm in September.

What is the temperature in September in Istanbul?

The average high-temperature, in September, in Istanbul, is 23.6°C (74.5°F), while the average low-temperature is 16.8°C (62.2°F).

How many days does it rain in September in Istanbul?

In Istanbul, Turkey, in September, during 7.3 rainfall days, 57.9mm (2.3") of precipitation is typically accumulated.

What is the water temperature in September in Istanbul?

In Istanbul, Turkey, the average seawater temperature in September is 22.8°C (73°F). For individuals prone to feeling cold, swimming in 23°C (73.4°F) is still regarded as intolerable. A wetsuit is not a necessity, but sunshine, wind, and air temperature are essential factors for relishing swimming at 22.8°C (73°F).

How many hours of daylight does Istanbul have in September?

The average length of the day in September is 12.5h.

How many hours of sunshine does Istanbul have in September?

The average sunshine in September in Istanbul is 8.1h.

What is the UV index reading in September in Istanbul?

The average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to the UV radiation.
Average temperature in September - Istanbul, Turkey
  • Average high temperature in September: 23.6°C

The warmest month (with the highest average high temperature) is August (26.7°C).
The month with the lowest average high temperature is January (8.5°C).

  • Average low temperature in September: 16.8°C

The month with the highest average low temperature is August (20°C).
The coldest month (with the lowest average low temperature) is February (3.1°C).

Average rainfall in September - Istanbul, Turkey
  • Average rainfall in September: 57.9mm

The wettest month (with the highest rainfall) is December (122.6mm).
The driest month (with the lowest rainfall) is July (31.6mm).

Average rainfall days in September - Istanbul, Turkey
  • Average rainfall days in September: 7.3 days

The month with the highest number of rainy days is January (17.5 days).
The month with the lowest number of rainy days is July (4.2 days).

Average snowfall days in September - Istanbul, Turkey
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (4.9 days).
Months with the lowest number of snowfall days are April, May, June, July, August, September and October (0 days).

Average sea temperature in September - Istanbul, Turkey
  • Average sea temperature in September: 22.8°C

The best month for swimming (with the highest average sea temperature) is August (24.9°C).
The coldest month (with the lowest average sea temperature) is February (7.8°C).

Average daylight in September / Average sunshine in September - Istanbul, Turkey
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.1h).
The month with shortest days is December (Average daylight: 9.3h).

  • Average sunshine in September: 8.1h

The month with most sunshine is July (Average sunshine: 10.4h).
The month with least sunshine is December (Average sunshine: 2.2h).

Average UV index in September - Istanbul, Turkey
  • Average UV index in September: 6

The month with the highest UV index is July (UV index 9).
The month with the lowest UV index is December (UV index 1).