São Paulo, the largest city in the Americas, sits on a plateau about 760–800 metres above sea level in southeast Brazil, roughly 65 km inland from the Atlantic, just south of the Tropic of Capricorn at approximately 23.55°S, 46.63°W. Its altitude gives it a humid subtropical climate (Köppen Cfa/Cfb) that is distinctly milder than the tropical coast, with a warm, wet summer and a cooler, drier winter. Being in the Southern Hemisphere, its seasons are reversed relative to the Northern.

Summer, from December to March, is warm and wet, with February the warmest month — average highs around 28–29°C. Hot spells can climb into the mid-to-high 30s, but the city's elevation and exposure to different air masses keep it from becoming as oppressive as the coast, and cooler days with highs of only 20–23°C can interrupt even midsummer. This is the rainy season, dominated by heavy afternoon and evening thunderstorms.

Winter, from June to August, is mild and comparatively dry, with July the coolest month — average highs around 22–23°C but chilly nights. Outbreaks of cold air from the south can drop night temperatures to around 5°C or lower, with occasional light frost on the outskirts, and rare cold days have kept highs near 10°C. Winter mornings often bring fog, especially in the outer districts, clearing to sunny, pleasant afternoons.

São Paulo is quite rainy, receiving roughly 1,350–1,450 mm a year with no truly dry month, but rainfall is strongly seasonal — concentrated from October to March and much lighter from June to August, when August is the driest month. Summer rain comes as intense convective thunderstorms that can cause flash flooding in the sprawling metropolis. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

São Paulo is famous for changeable, unpredictable weather: sitting where cool ocean air, warm inland air and occasional Antarctic outbreaks all meet, it can swing from warm to chilly within a single day, giving rise to the local saying that the city has 'four seasons in one day'. The urban heat island of the vast metropolis also lifts city-centre temperatures above the surrounding countryside.

To follow any single measurement in Sao Paulo 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.