Buenos Aires sits on the south bank of the Río de la Plata estuary in east-central Argentina, at approximately 34.60°S, 58.38°W. It has a humid subtropical climate (Köppen Cfa) with hot, stormy summers and cool, damp winters. Its position on the flat Pampas, with no mountains to shelter it, means the city is a battleground between the cold, dry Pampero wind from the south and warm, humid air from the north, giving it changeable weather year-round.

Summer runs from December to February and is hot and humid, with January the warmest month — average highs around 29–30°C and lows near 20°C. Muggy, unpleasant spells lasting a few days are typically broken by cooler southerly winds. Heat waves are common: temperatures have exceeded 40°C, with 41.5°C recorded in January 2022. It is also the rainiest season, thanks to frequent afternoon thunderstorms.

Winter, from June to August, is mild but often grey and humid. July, the coldest month, averages highs around 15–16°C and lows near 7°C, with frost occurring on average a couple of times a year in the colder suburbs. The maritime influence keeps genuinely cold days rare, though the Pampero can bring chilly spells. Snow is extraordinarily rare — the only notable snowfall in modern memory was in July 2007, the first since 1918.

Buenos Aires is fairly rainy, receiving around 1,000–1,150 mm a year with no true dry season, though winter is the least wet time. Rainfall peaks in the warmer months and the transitional autumn, often falling as heavy convective thunderstorms; exceptional downpours have caused serious flooding, such as the 300 mm that fell in a single day in 1985. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Two named winds shape the city's weather: the cold southerly Pampero, which sweeps in behind fronts and can trigger thunderstorms when it meets warm northern air, and the Sudestada, a persistent southeasterly that brings long spells of rain, cloud and cooler temperatures and can drive flooding in low-lying riverside areas. Winters are often cloudy with very high humidity.

To follow any single measurement in Buenos Aires more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.