You can find bitter cold, scorching heat, damp gloom and brilliant sunshine within the borders of Turkey's uncommonly varied climate. The rugged west and south coasts are firmly Mediterranean. Here, the rains virtually cease from June through September but can be heavy in the cool winter. Along the coastal arc from Izmir through Antalya to Adana, average highs in July and August reach 32°C/90°F, and even January days typically reach 12°C/54°F or better. Inland, the vast Anatolian plateau isn't too much warmer than the lowlands of Bulgaria or Hungary to the north, although there's noticeably the plateau is virtually dry until the light rains of October and dustings of snow in winter. The aridity of Anatolia makes big temperature swings possible. In August alone, Ankara has seen readings below 4°C/40°F and above 40°C/104°F. The lowlands adjoining Syria and Iraq are a few degrees warmer than the plateau: mid-summer highs in Diyarbakir, along the upper Tigris, often exceed 38°C/100°F.
The highlands across the northeast of Turkey – where many towns sit above 1500m/4900ft – can be shockingly cold in winter. Both Kars and Erzurum stay well below freezing on a typical January day. Sunny periods alternate with light snows that pile up slowly but steadily. After the thunderstorms of springtime come and go, northeast Turkey becomes pleasantly warm by day and cool by night during the summer. Yet another distinct climatic regime prevails along the Black Sea coast, including the Bosporus and Istanbul. This is Turkey's cloudiest and most temperate zone, where a substantial rain can fall any time of year. Cold air masses from Europe and Asia pick up moisture and warmth from the Black Sea, so that winters here are dependably on the cool side, with frequent rains (and perhaps a light snow every few weeks) but without the occasional frigid snaps of the interior. Summer showers aren't terribly numerous, and the days here are only a bit warmer than the mild, humid nights. The cool-season rains tend to start earlier in the autumn as you head toward the eastern end of the Black Sea coast.