Istanbul in September
In September, Istanbul has 49.0 mm (1.93 in) of rain, a daily high of 25.2 °C (77.4 °F) and a daily low of 18.2 °C (64.8 °F), as 1991-2020 model estimates; figures in brackets are converted. The daily high is a model estimate, adjusted against station records.
Last updated : back, with ERA5-Land model estimates.
Best time to visit Istanbul: September meets our rule. Expect 5.5 rain days (model estimate) and days that shorten by 1 h 17 min.
What September is like in Istanbul
- A cry of "Vira bismillah" sends fishing boats out from Kireçburnu pier in early September. Istanbul marks the end of the fishing ban with a send-off. Source: Sözcü, checked .
- Art and culture spread through Beyoğlu from late September into October for the Beyoğlu Culture Road Festival. The Atatürk Cultural Centre on Taksim Square is one of its stages. Source: Go Türkiye (Türkiye Tourism Promotion and Development Agency), checked .
- Raptors and other migrating birds glide over the strait past Çamlıca Hill in September and October. Source: Birdingplaces, checked .
Key figures
Weather in September, 1991-2020 model estimates
- Daily high
- 25.2 °C (77.4 °F)
- Daily low
- 18.2 °C (64.8 °F)
- Rain
- 49.0 mm (1.93 in) in the month
- Sunshine
- no data
Model estimate 1991-2020, not a weather station: ERA5-Land model estimates (Copernicus), computed by City by Month for the grid cell nearest the city. Daily high and Days with rain: model estimate, adjusted against station records. Licence: CC BY 4.0. Checked . How we make and test model estimates
Model estimate for the ERA5-Land grid cell at 41.0° N, 29.0° E, 4 km from the city centre point.
How we define and convert these figures
Notes. Sunshine: Not in our ERA5-Land estimates.
Daylight on 15 September 2026
- Sunrise
- 06:44 local time
- Sunset
- 19:14 local time
- Day length
- 12 h 29 min
Day length 1-30 September: 13 h 06 min to 11 h 49 min, -1 h 17 min.
Source: NOAA Solar Calculator equations, checked .
Month by month
Each month: daily high in °C, then rain in mm, 1991-2020 model estimates.
ERA5-Land model estimates 1991-2020, as above, checked .
This month against the year
| Measure | September | Rank |
|---|---|---|
| Daily high | 25.2 °C | 4th warmest |
| Daily low | 18.2 °C | 3rd warmest |
| Rain | 49.0 mm | 6th driest |
| Sunshine | no data | no data |
| Day length | 12 h 29 min | 6th longest |
Equal values share a rank. How we rank months
Istanbul in September, on average: 5.5 rain days (1 mm or more). Model estimate, adjusted against station records.
ERA5-Land model estimates 1991-2020, as above, checked .
Day length: NOAA solar equations, checked .
Public holidays this month
September 2026: none.
September 2027: none.
Typed from the official lists for 2026 and 2027 and re-checked, .
Source: Official public holiday list (vakithesaplama.diyanet.gov.tr) for 2026 and 2027, checked .
Same month in 8 model-estimate cities
Istanbul is warmer than 2 of our 8 model-estimate cities in September by mean daily high. How we rank cities
Closest high and low in September: Lisbon (0.5 °C apart), Porto (1.4), Sydney (5.2).
| City | Gap from Istanbul, °C | High, °C | Low, °C | Rain, mm | Sunshine, hours |
|---|---|---|---|---|---|
| Istanbul (this page) | — | 25.2 | 18.2 | 49.0 | no data |
| Lisbon (closest) | 0.5 | 26.1 | 18.2 | 31.2 | no data |
| Porto (closest) | 1.4 | 25.6 | 15.9 | 59.5 | no data |
| Sydney (closest) | 5.2 | 21.1 | 11.9 | 49.1 | no data |
| Mumbai | 5.7 | 29.8 | 24.9 | no data | no data |
| Bangkok | 7.0 | 32.1 | 25.2 | no data | no data |
| Delhi | 7.3 | 33.7 | 24.2 | no data | no data |
| Melbourne | 9.1 | 17.4 | 7.9 | 67.4 | no data |
Sources (1991-2020): ERA5-Land model estimates, checked . Each city's page names its grid cell. All sources in full on Methodology.
Sources
- Attribution: Copernicus Climate Change Service (2025): ERA5 Land hourly time-series data from 1950 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). DOI: 10.24381/ee82e357. Accessed on the check date shown. Generated using or contains modified Copernicus Climate Change Service information 2025. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. Licence: CC BY 4.0. Checked .
- NOAA Solar Calculator equations, computed locally, NOAA Global Monitoring Laboratory (method); City by Month (computation). Attribution: Computed with the NOAA Solar Calculator method (no NOAA endorsement implied). Licence: Method, not data. Checked .
Official sources
Cite this page: City by Month. "Istanbul in September: weather, daylight, holidays". https://citybymonth.com/cities/turkey/istanbul/september/. Last updated 8 November 2026.