Köppen climate classification in the context of "Subtropics"

Istanbul is the largest city in Turkey, constituting the country's economic, cultural, and historical heart. With a population over 15 million, it is home to 18% of the population of Turkey. Istanbul is among the largest cities in Europe and in the world by population. It is a city on two continents; about two-thirds of its population live in Europe and the rest in Asia. Istanbul straddles the Bosphorus—one of the world's busiest waterways—in northwestern Turkey, between the Sea of Marmara and the Black Sea. Its area of 5,461 square kilometers (2,109 sq mi) is coterminous with Istanbul Province. Under the Köppen climate classification, Istanbul's climate is considered a form of Mediterranean climate, with aspects of other temperate climate types.

The city now known as Istanbul developed to become one of the most significant cities in history. Byzantium was founded on the Sarayburnu promontory by Greek colonists, potentially in the seventh century BC. Over nearly 16 centuries following its reestablishment as Constantinople in 330 AD, it served as the capital of four empires: the Roman Empire (330–395), the Byzantine Empire (395–1204 and 1261–1453), the Latin Empire (1204–1261), and the Ottoman Empire (1453–1922). It was instrumental in the advancement of Christianity during Roman and Byzantine times, before the Ottomans conquered the city in 1453 and transformed it into an Islamic stronghold and the seat of the last caliphate. Although the Republic of Turkey established its capital in Ankara, palaces and imperial mosques still line Istanbul's hills as visible reminders of the city's previous central role. The historic centre of Istanbul is a UNESCO World Heritage Site.

A Mediterranean climate (/ˌmɛdɪtəˈreɪniən/ MED-ih-tə-RAY-nee-ən), also called a dry summer climate, described by Köppen and Trewartha as Cs, is a temperate climate type that occurs in the lower mid-latitudes (normally 30 to 44 north and south latitude). Such climates typically have dry summers and wet winters, with summer conditions being hot and winter conditions typically being mild. These weather conditions are typically experienced in the majority of Mediterranean-climate regions and countries, but remain highly dependent on proximity to the ocean, elevation, and geographical location.

The dry summer climate is found throughout the warmer middle latitudes, affecting almost exclusively the western portions of continents in relative proximity to the coast. The climate type's name is in reference to the coastal regions of the Mediterranean Sea, which mostly share this type of climate, but it can also be found in the Atlantic portions of Iberia and Northwest Africa, the Pacific portions of the United States and Chile, extreme west areas of Argentina, the southwest tip of South Africa, parts of Southwest and South Australia, and parts of Central Asia. They tend to be found in proximity (both poleward and near the coast) of desert and semi-arid climates, and equatorward of oceanic climates.

Europe is generally characterized by a temperate climate. Most of Western Europe has an oceanic climate, in the Köppen climate classification, featuring cool to warm summers and cool winters with frequent overcast skies. Southern Europe has a distinctively Mediterranean climate, which features warm to hot, dry summers and cool to mild winters and frequent sunny skies. Central-eastern Europe is classified as having a humid continental climate, which features warm to hot summers and cold winters.

In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small; they usually differ only in the amount of precipitation.

In temperate climates, not only do latitudinal positions influence temperature changes, but various sea currents, prevailing wind direction, continentality (how large a landmass is) and altitude also shape temperate climates.

Polar deserts are the regions of Earth that fall under an ice cap climate (EF under the Köppen classification). Despite rainfall totals low enough to normally classify as a desert, polar deserts are distinguished from true deserts (BWh or BWk under the Köppen classification) by low annual temperatures and evapotranspiration. Most polar deserts are covered in ice sheets, ice fields, or ice caps, and they are also called white deserts.

Polar deserts are one of two polar biomes, the other being Arctic tundra. These biomes are located at the poles of Earth, covering much of the Antarctic in the southern hemisphere, and in the northern hemisphere extending from the Arctic into North America, Europe and Asia. Unlike the tundra that can support plant and animal life in the summer, polar deserts are largely barren environments, comprising permanent, flat layers of ice; due to the scarcity of liquid water, the same is also true of the few ice-free areas. However, there is evidence of some life in this seemingly inhospitable landscape: sediments of organic and inorganic substances in the thick ice hosting microbial organisms closely related to cyanobacteria, able to fix carbon dioxide from the melting water.

Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them. The climate of a location is affected by its latitude, longitude, terrain, altitude, land use and nearby water bodies and their currents.

Climates can be classified according to the average and typical variables, most commonly temperature and precipitation. The most widely used classification scheme is the Köppen climate classification. The Thornthwaite system, in use since 1948, incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it. The major classifications in Thornthwaite's climate classification are microthermal, mesothermal, and megathermal. Finally, the Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region.

The Ryukyu Islands (Japanese: 琉球列島, Hepburn: Ryūkyū Rettō), also known as the Nansei Islands (南西諸島, Nansei Shotō; lit. 'Southwest Islands') or the Ryukyu Arc (琉球弧, Ryūkyū-ko), are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ryukyu Islands are divided into the Satsunan Islands (Ōsumi, Tokara and Amami) and Okinawa Prefecture (Daitō, Miyako, Yaeyama, Senkaku, Okinawa, Sakishima Islands (further divided into the Miyako and Yaeyama Islands), and Yonaguni as the westernmost). The larger ones are mostly volcanic islands and the smaller mostly coral. The largest is Okinawa Island.

The climate of the islands ranges from humid subtropical climate (Köppen climate classification Cfa) in the north to tropical rainforest climate (Köppen climate classification Af) in the south. Precipitation is very high and is affected by the rainy season and typhoons. Except the outlying Daitō Islands, the island chain has two major geologic boundaries, the Tokara Strait (between the Tokara and Amami Islands) and the Kerama Gap (between the Okinawa and Miyako Islands). The islands beyond the Tokara Strait are characterized by their coral reefs.

A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers, and cold (sometimes severely cold in the northern areas) and snowy winters. Precipitation is usually distributed throughout the year, but often these regions do have dry seasons. The definition of this climate in terms of temperature is as follows: the mean temperature of the coldest month must be below 0 °C (32.0 °F) or −3 °C (26.6 °F) depending on the isotherm, and there must be at least four months whose mean temperatures are at or above 10 °C (50 °F). In addition, the location in question must not be semi-arid or arid. The cooler Dfb, Dwb, and Dsb subtypes are also known as hemiboreal climates. Although amount of snowfall is not a factor used in defining the humid continental climate, snow during the winter in this type of climate is almost a guarantee, either intermittently throughout the winter months near the southern or coastal margins, or persistently throughout the winter months elsewhere in the climate zone.

Humid continental climates are generally found between latitudes 40° N and 60° N, within the central and northeastern portions of North America, Europe, and Asia. Occasionally, they can also be found at higher elevations above other more temperate climate types. They are rare in the Southern Hemisphere, limited to isolated high altitude locations, due to the larger ocean area at that latitude, smaller land mass, and the consequent greater maritime moderation.

The Bulgarian Black Sea Coast (Bulgarian: Черноморие, romanized: Chernomorie), also known as the Bulgarian Riviera, covers the entire eastern bound of Bulgaria stretching from the Romanian Black Sea resorts in the north to European Turkey in the south, along 378 km of coastline. White and golden sandy beaches occupy approximately 130 km of the 378 km long coast. The region is an important center of tourism during the summer season (May–October), drawing millions of foreign and local tourists alike and constituting one of the country's most popular tourist destinations. Prior to 1989 the Bulgarian Black Sea coast was internationally known as the Red Riviera. Since the fall of the Iron Curtain, however, its nickname has been changed to the Bulgarian Riviera.

The Bulgarian Black Sea Coast has a humid subtropical climate (Köppen climate classification Cfa), with considerable maritime and continental influences. The area's average air temperature in the summer is about 28 °C, with the average water temperature at 26 °C. There are more than 240 hours of sunshine in May and September and more than 300 hours in July and August.