Istanbul — Climate Guide
Monthly temperatures, rainfall, humidity and best time to visit Istanbul.
Istanbul climate at a glance
| Month | High | Low | Rain | Humidity |
|---|---|---|---|---|
| Jan | 8°C | 3°C | 109mm | 81% |
| Feb | 8°C | 3°C | 80mm | 79% |
| Mar | 11°C | 5°C | 69mm | 78% |
| Apr | 16°C | 9°C | 51mm | 74% |
| May | 20°C | 13°C | 38mm | 71% |
| Jun | 25°C | 17°C | 34mm | 67% |
| Jul | 27°C | 20°C | 34mm | 65% |
| Aug | 28°C | 21°C | 25mm | 64% |
| Sep | 24°C | 17°C | 58mm | 68% |
| Oct | 19°C | 13°C | 81mm | 74% |
| Nov | 13°C | 9°C | 98mm | 80% |
| Dec | 9°C | 4°C | 120mm | 83% |
Climate overview
Istanbul straddles the Bosphorus strait between the Black Sea to the north and the Sea of Marmara to the south, and both seas shape its weather. It sits on the boundary between a Mediterranean climate (Csa) and a humid subtropical one (Cfa), which shows in its warm, mostly dry summers and cool, damp, changeable winters.
Summers average 27–28°C with high humidity from the surrounding water, while winters hover around 8–9°C by day. Annual rainfall is about 830 mm, falling mostly from October to March. Northerly winds from the Black Sea can bring sudden cold snaps and, in some winters, heavy snow.
Köppen classification: Csa/Cfa — Mediterranean / humid subtropical (transitional)
Istanbul through the seasons
Winter
December – FebruaryWinters are cool, cloudy and wet, with highs of 8–9°C and lows of 3–4°C. December is the wettest month at around 120 mm. Snow falls most years, and when a cold air mass crosses the Black Sea it can bring significant 'lake-effect' snowfalls that briefly disrupt traffic and ferries.
Spring
March – MaySpring is changeable but increasingly pleasant, warming from 11°C in March to 20°C in May. April brings the city's famous tulip displays. Rain becomes less frequent through May, and sea fog can occasionally form over the Bosphorus in the mornings.
Summer
June – AugustSummers are warm and humid, with highs around 25–28°C and lows near 20–21°C. Rainfall is low and sunshine abundant. The poyraz, a northeasterly wind off the Black Sea, often keeps the city cooler and breezier than inland Turkey.
Autumn
September – NovemberSeptember remains warm at about 24°C and is one of the best months to visit. Rain picks up in October and November, and by late autumn highs are down to 13°C with grey skies becoming more common.
What makes Istanbul's weather distinctive
Istanbul's position between two seas creates real variation within the city. Northern districts near the Black Sea are typically cooler and wetter, while southern areas along the Marmara coast are milder. Weather can also change quickly: a sunny morning can turn to rain by afternoon as winds shift.
The other notable feature is the poyraz and lodos pair of winds. The northeasterly poyraz brings cool, clear air, while the southwesterly lodos is warm and gusty and can cause rough seas and ferry cancellations.
Best time to visit Istanbul
The best times to visit Istanbul are April to June and September to October. Temperatures of 16–25°C are ideal for walking between mosques, bazaars and waterfront neighbourhoods, and rainfall is moderate. July and August are warm, humid and busy; winter is quieter and cheaper but often wet and grey.
What to pack
- Comfortable walking shoes for steep, cobbled streets
- Layers you can add or remove as the weather changes during the day
- A compact umbrella or rain jacket from October to April
- A scarf (for women) and clothing covering shoulders and knees for mosque visits
- A warm coat in winter — damp cold feels colder than the thermometer suggests
Frequently asked questions
Does it snow in Istanbul?
Yes, most winters see some snow, usually in January or February. Occasionally a cold spell over the Black Sea brings heavy snowfall that lasts several days.
What is the rainiest month in Istanbul?
December is the wettest month, averaging about 120 mm. The period from October to March brings most of the year's rain.
Is Istanbul very hot in summer?
Not extremely. Average highs in July and August are 27–28°C, but humidity can make it feel warmer. Sea breezes usually keep it more comfortable than inland cities.
Related reading
About this data: Monthly figures are rounded long-term averages consistent with published climate normals from national weather services and the World Meteorological Organization. Individual years can differ noticeably, and recent summers in many cities have run warmer than these averages. For current conditions and the next few days, use the live dashboard (data from WeatherAPI.com). Spotted an error? Tell us and we will correct it.
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