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Istanbul weather by month
Historical averages 2016–2025 · not a forecast
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When is the best time to visit Istanbul?
For a warm holiday, the best week has been 23–29 June (Weather Index 97). Favourable start dates for a 7-day trip run from 14 June to 4 July. July and August are warmest (28°C), August is driest and July has the most sun.
- Warmest
- July and August 28°C
- Coolest
- January 9°C
- Driest
- August 9% rain-day chance
- Wettest
- January and December 45% rain-day chance
- Sunniest
- July 14 hours a day
A rain day has 1 mm or more, snow included, so a short shower counts. Monthly averages below give the amounts.
Monthly averages in Istanbul
Istanbul historical monthly estimates, 2016–2025. Temperatures and sunshine are daily averages.
| Month | High (°C) | Low (°C) | Rain-day chance (%) | Expected rain days | Precipitation (mm/month) | Sunshine (hours/day) |
|---|---|---|---|---|---|---|
| January | 9.4 | 6.0 | 44.8 | 13.9 | 103.2 | 6.2 |
| February | 10.0 | 6.2 | 40.0 | 11.2 | 73.0 | 7.5 |
| March | 11.8 | 7.3 | 35.8 | 11.1 | 67.9 | 8.8 |
| April | 15.5 | 10.0 | 29.0 | 8.7 | 52.5 | 10.6 |
| May | 19.9 | 14.5 | 24.8 | 7.7 | 39.6 | 12.1 |
| June | 25.4 | 19.7 | 17.0 | 5.1 | 25.1 | 13.4 |
| July | 28.0 | 22.1 | 12.6 | 3.9 | 32.4 | 13.6 |
| August | 28.1 | 22.8 | 9.0 | 2.8 | 14.8 | 12.8 |
| September | 24.8 | 19.9 | 22.3 | 6.7 | 40.8 | 11.0 |
| October | 19.9 | 15.6 | 23.9 | 7.4 | 52.1 | 8.8 |
| November | 16.2 | 12.3 | 32.0 | 9.6 | 82.6 | 7.3 |
| December | 11.8 | 8.5 | 45.5 | 14.1 | 96.0 | 5.7 |
Each month averages its own days. Precipitation includes snow. About the data
Sources
Open-Meteo · 1 Jan 2016 – 31 Dec 2025
- Open-Meteo Historical Weather API
- Local days, 2016–2025, every year weighted equally. Each weekly chart averages its own seven days, without smoothing.
- Shading shows the 10th–90th percentile of past days, not forecast confidence.
- A rain day has at least 1 mm, snow included. The last weekly period has eight days.
- Wind is the average daytime (10:00–18:00) maximum, not gusts. Daylight is calculated from latitude. Missing readings stay blank.
- Mugginess (dew point) comes from the original daily summaries, on UTC days.
- The live two-week forecast comes from the Open-Meteo Weather Forecast API. The Weather Index does not use it.