Climate of Buenos Aires  Buenos Aires, the capital of Argentina, has a temperate climate, which is classified as a humid subtropical climate ("Cfa") under the Köppen climate classification with four distinct seasons. Summers are hot and humid with frequent thunderstorms while winters are cool and drier with frosts that occurs on average twice per year. Spring and fall are transition seasons characterized by changeable weather. At the central observatory, the highest recorded temperature is while the lowest recorded temperature is . Different climatic factors influence the climate of Buenos Aires. The semi–permanent South Atlantic High influences its climate throughout the year by bringing in moist winds from the northeast, which bring most of the precipitation to the city in the form of frontal systems during winter or storms produced by cyclogenesis in autumn and winter. The hot temperatures and high insolation in the summer months form a low pressure system called the Chaco Low over northern Argentina, generating a pressure gradient that brings moist easterly winds to the city – because of this, summer is the rainiest season. In contrast, this low pressure system weakens in the winter, which combined with strong southerly winds results in a drier season due to weaker easterly winds. Being located in the Pampas, Buenos Aires has variable weather due to the passage of contrasting air mass – the cold, dry Pampero from the south and warm, humid tropical air from the north. The coastal location results in a strong maritime influence, causing extreme temperatures (hot or cold) to be rare. Buenos Aires is located in the humid subtropical climate zone (Köppen climate classification: "Cfa"). Due to the maritime influences from the adjoining Atlantic Ocean, its climate is temperate with extreme temperatures (both hot and cold) being rare. Thus, cold air coming directly from the south are moderated by the Atlantic Ocean and warmer than winds from the southwest (which are not moderated by it). The climate of Buenos Aires is dominated by the semi–permanent South Atlantic High throughout the year. This brings in moist winds from the northeast, which brings most of the precipitation to the city. During winter, it brings in frontal systems responsible for precipitation in the city. In autumn and summer, it produces storms that are generally located north of the city and produces strong winds from the south or southeast that can occasionally lead to the swelling of the Río de la Plata, flooding coastal areas. The South Pacific High is the origin of polar air masses that are responsible for the coldest temperatures and result in clear and very dry conditions.