Mendoza sits in western Argentina at the foot of the Andes, on an arid plain at around 750 metres above sea level in the rain shadow of the mountains, at approximately 32.89°S, 68.83°W. Cut off from Pacific moisture by the high Andes, it has an arid, continental desert climate (Köppen BWk) — hot, dry summers and cool, dry winters — with abundant sunshine, very low rainfall, and a wide day-to-night temperature range. Being in the Southern Hemisphere, its seasons are reversed relative to the Northern.

Summer, from December to February, is hot, dry and sunny, with January the warmest month — average highs around 31–32°C and hot spells reaching the high 30s — tempered by very low humidity and cool nights thanks to the elevation. This is the wetter part of an otherwise dry year, when the little rain that falls comes mainly as brief, occasionally violent afternoon thunderstorms, sometimes with damaging hail that threatens the region's vineyards.

Winter, from June to August, is cool, dry and sunny, with July the coolest month — average highs around 15°C and cold nights that regularly fall to freezing, bringing frost. Snow is rare in the city but caps the Andes just to the west. Days are bright and mild, and the season is very dry, with clear skies the norm and a large gap between mild days and cold nights.

Mendoza is very dry, receiving only around 220–250 mm of rain a year — desert levels — because the Andes block moist Pacific air, with what little falls concentrated in the summer as thunderstorms; winter is almost completely dry. The region depends on Andean snowmelt, channelled through irrigation, to water its famous vineyards. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Mendoza's defining weather feature is the Zonda, a hot, dry föhn wind that descends from the Andes, sometimes raising the temperature dramatically within hours, plunging humidity and raising dust before a cold front arrives. The dry, sunny, Andean-foothill climate — with its irrigation-fed vineyards, cool nights and hail-bearing summer storms — is what makes Mendoza the heart of Argentina's wine country.

To follow any single measurement in Mendoza 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.