Forget the stereotypical Istanbul image of a city of 1001 Nights situated in the desert amidst date palms. Despite its fairly southerly latitude (which is about the same as Naples or Barcelona), it snows in this city – a lot occasionally. Some winters go by only with rain, though.
Summers are as hot as expected. High relative humidity levels and the ‘concrete-island effect’ only make things worse. Expect temperatures of up to 40° C for the hottest days of the year. Rainfall is a very remote possibility during summer. Even if it rains, you only need to wait 10 minutes for the sun to reappear again.
Springs (April-May) and autumns (late September-early November) are the most pleasant times to be in this city, as it’s neither too cold nor too hot. Although not a “rainy season” in a typical sense, be prepared to experience rainy days. However, it’s not such a big problem, since streets of Istanbul are suddenly filled by umbrella sellers as soon as it starts raining. Although the umbrellas they provide are a little shoddy, going rate is only YTL 5 –about US$ 3- per umbrella (though you can find much better umbrellas for that price at shops if you look around a bit).
Also take note that being a huge city, different parts of Istanbul may experience different weather conditions at the same time. For example, at the same moment, it can be heavily raining in Sarıyer in the north, mildly raining in Levent (northern terminus of metro line), while Taksim, the southern terminus of metro line, is having a perfectly sunny day. In general, northernmost parts of the city (nearer to Black Sea) have higher levels of humidity and thus tend to be rainier. The Asian Side (at least its southern coastal part) tends to have milder conditions than the European side (i.e. warmer in winter, cooler in summer). In fact, the Princes’ Islands have even milder weather than the Asian Side (which lets subtropical plants such as bananas or bougainvilleas, which can’t grow anywhere else in Istanbul because of winter lows, to flourish there).
|Daily highs (°C)||7||8||10||15||20||25||27||27||24||19||13||10|
|Nightly lows (°C)||2||2||4||8||12||16||18||19||16||12||8||5|