September · Turkey
Best time to visit Istanbul in September Weather, crowds & prices
Weather in Istanbul in September
Average temperature 21°C, 49 mm of rain, about 29 days with 6+ hours of sunshine and 71% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
9.3/10
Ranked #2 of 12 months
- Avg temp
- 21°C
- Rainfall
- 49 mm
- Humidity
- 71%
- Days with 6h+ sun
- 29
- Crowd Density
- Moderate Crowds
- Average Expenses
- $$$ · Peak Season Rates ($$$)
September in Istanbul scores 9.3/10 for sightseeing and cultural travel - one of the top 12-month picks (#2). Expect around 21°C, 49 mm of rain, and roughly 29 days with 6+ hours of sunshine this month.
Bosphorus ferries and storied quarters shine brightest in mild April through June.
September is one of the strongest months in Istanbul (2nd)
September averages 21°C (70°F) — pleasant for mornings and evenings on foot in the city, with a midday break when the sun is strongest.
Rainfall runs 49 mm, so plan one flexible day in three; you still get about 29 days with 6+ hours of sunshine and 12.5 hours of daylight.
A 9.3/10 puts this among the year's best months in Istanbul (2nd of 12); only June scores higher, at 9.4/10.
Pack light clothing, a hat and real sun protection, a packable rain layer.
Figure on peak pricing, with crowds are moderate. You are paying the year's highest rates for the year's best conditions — book early or shift a few weeks either side.
Frequently asked
- What is the weather like in Istanbul in September?
- In September, Istanbul averages 21°C, 49 mm of rain, and about 29 days with 6+ hours of sunshine. Its climate-comfort score is 9.3/10.
- Is September a good time to visit Istanbul?
- September earns a 9.3/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Istanbul in September?
- Expect about 49 mm of rain in September. Average humidity is 71% and there are about 29 days with 6+ hours of sunshine.
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