Istanbul climate
Istanbul is warmest in August, with average highs of 28 °C, and coldest in February, when nights average 4.0 °C. December is the wettest month (98 mm) and July the driest (20 mm). Figures are 1991–2020 climate normals.
Across a full year Istanbul averages 677 mm of rain, 85 days above 25 °C and 7 days below freezing.
Turkey · population 15,701,602 · 1991–2020 normals
Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month
- Warmest month August 28 °C
- Coldest month February 4.0 °C
- Driest month July 20 mm
- Wettest month December 98 mm
- Least cloud July 19 % cloud
- Hottest on record July 35 °C
- Coldest on record January -7.8 °C
- Warmest sea August 24 °C
What to expectIstanbul through the year
Istanbul has a clear annual cycle: average daily highs run from 8.8 °C in February to 28 °C in August, a swing of 18 °C in mean temperature across the year.
Counted across a normal year, 85 days a year reach 25 °C, 11 of them reach 30 °C, 7 nights drop below freezing. The warmest reading in the 1991–2020 record is 35 °C, in July.
Rain is strongly seasonal. December averages 98 mm against 20 mm in July — 5.0 times as much. Planning around the dry months matters more here than planning around temperature.
The sea off Istanbul is warmest in August at 24 °C and coldest in February at 8.0 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 8.2 °C | 85 mm | 67 % |
| February | 8.8 °C | 71 mm | 64 % |
| March | 11.0 °C | 72 mm | 59 % |
| April | 15.1 °C | 47 mm | 53 % |
| May | 20.0 °C | 36 mm | 45 % |
| June | 24.9 °C | 34 mm | 30 % |
| July | 27.6 °C | 20 mm | 19 % |
| August | 27.9 °C | 20 mm | 21 % |
| September | 24.1 °C | 45 mm | 33 % |
| October | 19.2 °C | 78 mm | 51 % |
| November | 14.3 °C | 72 mm | 60 % |
| December | 10.1 °C | 98 mm | 67 % |
Temperature month by month
| Month | Avg high | Avg low | Mean | Record high | Record low | Days above 25 °C | Days above 30 °C | Days below 0 °C |
|---|---|---|---|---|---|---|---|---|
| January | 8.2 °C | 4.0 °C | 6.2 °C | 17.8 °C | -7.8 °C | 0 | 0 | 3 |
| February | 8.8 °C | 4.0 °C | 6.4 °C | 18.8 °C | -6.8 °C | 0 | 0 | 2 |
| March | 11.0 °C | 5.4 °C | 8.2 °C | 22.1 °C | -4.0 °C | 0 | 0 | 1 |
| April | 15.1 °C | 8.6 °C | 11.9 °C | 26.8 °C | 1.5 °C | 0 | 0 | 0 |
| May | 20.0 °C | 13.5 °C | 16.8 °C | 30.6 °C | 5.0 °C | 2 | 0 | 0 |
| June | 24.9 °C | 18.3 °C | 21.6 °C | 34.8 °C | 11.8 °C | 15 | 1 | 0 |
| July | 27.6 °C | 21.0 °C | 24.2 °C | 35.3 °C | 15.9 °C | 27 | 4 | 0 |
| August | 27.9 °C | 21.7 °C | 24.6 °C | 34.9 °C | 16.0 °C | 28 | 6 | 0 |
| September | 24.1 °C | 18.3 °C | 21.1 °C | 34.6 °C | 11.7 °C | 12 | 0 | 0 |
| October | 19.2 °C | 14.3 °C | 16.6 °C | 30.9 °C | 5.8 °C | 1 | 0 | 0 |
| November | 14.3 °C | 9.9 °C | 12.1 °C | 23.1 °C | 0.7 °C | 0 | 0 | 0 |
| December | 10.1 °C | 6.2 °C | 8.2 °C | 21.4 °C | -1.8 °C | 0 | 0 | 1 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind | Sea temp |
|---|---|---|---|---|---|---|---|
| January | 85 mm | 12 | 9.6 h/day | 67 % | 79 % | 23 km/h | 8.9 °C |
| February | 71 mm | 11 | 11 h/day | 64 % | 78 % | 23 km/h | 8.0 °C |
| March | 72 mm | 10 | 12 h/day | 59 % | 76 % | 22 km/h | 8.7 °C |
| April | 47 mm | 8 | 13 h/day | 53 % | 76 % | 20 km/h | 11.3 °C |
| May | 36 mm | 6 | 14 h/day | 45 % | 76 % | 19 km/h | 16.0 °C |
| June | 34 mm | 6 | 15 h/day | 30 % | 73 % | 19 km/h | 20.9 °C |
| July | 20 mm | 3 | 15 h/day | 19 % | 70 % | 21 km/h | 23.4 °C |
| August | 20 mm | 3 | 14 h/day | 21 % | 70 % | 23 km/h | 24.2 °C |
| September | 45 mm | 6 | 12 h/day | 33 % | 70 % | 21 km/h | 22.4 °C |
| October | 78 mm | 8 | 11 h/day | 51 % | 76 % | 21 km/h | 19.1 °C |
| November | 72 mm | 9 | 9.9 h/day | 60 % | 77 % | 21 km/h | 15.1 °C |
| December | 98 mm | 13 | 9.2 h/day | 67 % | 78 % | 23 km/h | 11.5 °C |
How Istanbul compares
The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.
| Destination | Summer high | Winter low | Rain per year | Days above 25 °C |
|---|---|---|---|---|
| Istanbul | 28 °C | 4.0 °C | 677 mm | 85 |
| Bağcılar · Turkey | 27 °C | 3.6 °C | 677 mm | 78 |
| Esenyurt · Turkey | 27 °C | 3.7 °C | 635 mm | 76 |
| Arnavutköy · Turkey | 28 °C | 2.7 °C | 658 mm | 86 |
| Gebze · Turkey | 28 °C | 2.1 °C | 684 mm | 83 |
| İzmit · Turkey | 28 °C | 1.4 °C | 919 mm | 104 |
| Bursa · Turkey | 30 °C | 1.8 °C | 861 mm | 114 |
Where Istanbul ranks
| Ranking | Position | Value |
|---|---|---|
| Best beach destinations in Asia in August | 3rd of 50 | 99/100 |
| Best beach destinations in Asia in July | 9th of 50 | 97/100 |
| Best beach destinations in the world in August | 10th of 50 | 99/100 |
| Best beach destinations in the world in July | 28th of 50 | 97/100 |
| Best beach destinations in Asia in June | 33rd of 50 | 82/100 |
Planning a trip? See the best time to visit Istanbul.
QuestionsCommon questions about Istanbul’s climate
When is the best time to visit Istanbul?
That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, September sit closest to 20 °C on average, August is the warmest month and July the driest. The month-by-month table above has the full picture.
How hot does Istanbul get?
In August, the warmest month, daily highs average 28 °C. About 11 days a year pass 30 °C. The highest value in the 1991–2020 record is 35 °C.
How cold does it get in winter?
Nights average 4.0 °C in February, the coldest month. A normal year has 7 nights below freezing.
Which month is wettest in Istanbul?
December, averaging 98 mm over 13 days with rain. The driest month is July with 20 mm. The year as a whole averages 677 mm.
Are these figures a forecast?
No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Istanbul rather than what any particular week will bring. Individual years can differ substantially from the normal.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Data point
- 41.014°, 28.950° (the coordinates the reanalysis values are taken for)
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.