🇺🇾Uruguay

Uruguay (176,215 km²) spans 30°–35°S, 53°–58°W across the southeastern South American plains between the Río de la Plata estuary and Brazil, forming a compact territory of gently rolling hills (cuchillas) rarely exceeding 500 m elevation, with a temperate humid subtropical climate (Köppen Cfa) strongly modulated by Atlantic maritime influence and the absence of major topographic barriers.

The climate features warm, humid summers (January highs of about 25–32°C) and mild winters (July highs of 14–18°C, nights of 7–9°C) with rare temperature extremes, no true dry season, and about 1,000–1,500 mm annual precipitation distributed relatively evenly through the year.

The fertile Pampean grasslands (campos) dominate the interior rolling hills and support extensive cattle ranching and agriculture (wheat, soybeans, rice), while the Atlantic coastal plain from Punta del Este northward to the Brazilian border features coastal lagoons, dunes, and palm groves (Butia odorata).

The Río Uruguay and Río de la Plata borders create humid riparian microclimates, while the northern interior near Salto and Artigas experiences warmer summers and milder, drier winters. Uruguay's small size, agricultural export dependence, and reliance on hydroelectric power from the Río Negro and Río Uruguay dams render it acutely vulnerable to accelerating climate extremes: intensifying droughts devastate pasture and crops while threatening urban water supplies, severe flooding disrupts infrastructure and agriculture, and shifting precipitation variability destabilizes the energy-water nexus critical to the economy.

Montevideo (capital, 34.9°S, elevation 43 m on the Río de la Plata) exemplifies the Atlantic-moderated subtropical climate, with highs around 28°C in January and 15°C in July (nights of about 19°C and 7°C) and approximately 1,100 mm annual precipitation fairly evenly distributed through the year.

The severe 2022–2023 La Niña drought damaged Uruguay, causing agricultural losses exceeding $1 billion, and triggered a national water-supply emergency when the reservoirs feeding Montevideo, including Paso Severino, nearly ran dry in 2023; from May 2023 brackish water flowing up the Santa Lucía River reached the taps of 60% of the national population, sparking protests.

The severe January 2022 heatwave broke records across Uruguay when temperatures reached 44°C in Florida, tying the national record, and exceeded 40°C in 14 of 19 departments, triggering wildfire outbreaks. The severe April 2016 tornado struck the city of Dolores in Soriano Department, southwestern Uruguay, when an intense F3 tornado, rare for South America, killed four to five people, injured over 200, and destroyed hundreds of homes and buildings.

The severe May 2007 flooding struck central Uruguay when torrential rains swelled the Yí, Negro and Olimar rivers, triggering severe floods in Durazno, Mercedes, and Treinta y Tres, displacing thousands of people and submerging farmland.

The May–June 2017 Río Uruguay flood forced people from their homes in Salto.

Salto (northern Río Uruguay, 31.4°S, 48 m elevation) has January highs around 32°C and July highs of 18°C with nights near 7°C, and about 1,350 mm rainfall, while Punta del Este on the Atlantic coast sees highs of about 25°C in January and 14°C in July (nights near 9°C) with cooler ocean-moderated summers and 1,050 mm precipitation. Pampean drought variability linked to ENSO and Atlantic SST patterns threatens Uruguay's water security, agricultural viability, and energy generation as climate change intensifies hydrological extremes.

Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 0.7°C.