An extratropical cyclone swept across Uruguay between Thursday afternoon and early Friday, producing wind gusts above 120 km/h (75 mph), severe thunderstorms and more than 75 mm (3 inches) of rain.
The storm prompted Uruguay’s government to declare a red alert along the southeastern coast from Arroyo Pando in Canelones to Aguas Dulces in Rocha. Mobility was restricted, government activities were suspended and the National Emergency System was activated during the most dangerous phase of the storm.
The red alert remained in effect from 9 p.m. on August 6 until 4 a.m. on August 7. An orange warning from the Uruguayan Institute of Meteorology, known as Inumet, was subsequently downgraded to yellow at 6 a.m. and lifted at 7:30 a.m.
Although the warnings have now ended, the storm left one person dead, tens of thousands of households without electricity and damage across several departments.
Gobierno decretó alerta de nivel rojo desde la hora 21.00 hasta las 04.00, desde arroyo Pando hasta Aguas Dulces. Los detalles con @Martinabreu20 pic.twitter.com/AXrJD1AxeZ
— Subrayado (@Subrayado) August 6, 2026
Why did the storm become so powerful?
The severe weather was associated with the deepening of an extratropical cyclone near Uruguay.
Unlike tropical cyclones, these systems obtain their energy from strong temperature contrasts between warm and cold air masses. As pressure falls at the centre, winds accelerate around the developing low-pressure system.
The arrival of colder air caused winds to turn toward the south and southwest, exposing Uruguay’s southern and southeastern coastline to prolonged onshore winds and increasingly rough seas.
Inumet forecast sustained winds of 60 to 80 km/h (37 to 50 mph), with gusts of 90 to 120 km/h (56 to 75 mph) and locally higher speeds. Around Punta del Este, southwest winds were expected to produce gusts between 100 and 120 km/h (62 to 75 mph).
The risk was increased by soil already saturated following earlier rainfall. Waterlogged ground provides less support for trees, making them more likely to fall when powerful winds arrive.
Observations released by Inumet confirmed that the strongest gust reached 121 km/h (75 mph) at the automatic weather station in Lavalleja at 2:40 p.m. on Thursday.
Santa Teresa in Rocha recorded 119 km/h (74 mph), narrowly missing the highest value. Trinidad in Flores registered 109 km/h (68 mph), while a gust of 107 km/h (66 mph) was measured in Prado, Montevideo.
The maximum gusts recorded between midnight on August 6 and 10 a.m. on August 7 were:
- Lavalleja: 121 km/h (75 mph) at 2:40 p.m.
- Santa Teresa, Rocha: 119 km/h (74 mph) at 4:30 p.m.
- Trinidad, Flores: 109 km/h (68 mph) at 2:20 p.m.
- Prado, Montevideo: 107 km/h (66 mph) at 7:45 p.m.
- Punta del Este, Maldonado: 100 km/h (62 mph)
- Laguna del Sauce, Maldonado: 99 km/h (62 mph) at 9:21 p.m.
- Melo, Cerro Largo: 93 km/h (58 mph) at 4:20 p.m.
- Salto: 92 km/h (57 mph) at 1:40 p.m.
- Illescas, Florida: 91 km/h (57 mph) at 2:40 p.m.
- Rocha: 90 km/h (56 mph) at 10:40 p.m.
The observations demonstrate the cyclone’s broad reach. Although the red alert concentrated on the southeastern coast, damaging winds occurred across inland, southern and western Uruguay.
Barrio Uruguay, 🇺🇾 SALTO . Vía 📹 seguidor pic.twitter.com/OG2rQG9K86
— Matias Clima Meteo 🇺🇾 𝕏 (@AficionadoMeteo) August 6, 2026
Rainfall reaches 76 mm in Colonia
The storm also produced widespread heavy rain. The highest accumulation was recorded at El Cerro in the department of Colonia, where 76 mm (3 inches) fell between 7 a.m. on Thursday and 7 a.m. on Friday.
Laguna Merín in Cerro Largo received 74 mm (2.9 inches). Villa Rodríguez in San José and Santa Lucía in Canelones each recorded 60 mm (2.4 inches).
Inumet reported the following highest 24-hour rainfall totals:
- El Cerro, Colonia: 76 mm (3 inches)
- Laguna Merín, Cerro Largo: 74 mm (2.9 inches)
- Villa Rodríguez, San José: 60 mm (2.4 inches)
- Santa Lucía, Canelones: 60 mm (2.4 inches)
- Nueva Helvecia, Colonia: 58 mm (2.3 inches)
- Cufré, Colonia: 58 mm (2.3 inches)
- Conchillas, Colonia: 57.5 mm (2.3 inches)
- Colonia Valdense, Colonia: 55.5 mm (2.2 inches)
- Tarariras, Colonia: 54 mm (2.1 inches)
- Chacra Policial, Canelones: 53 mm (2.1 inches)
Several of the highest totals were concentrated in Colonia. The combination of saturated ground and strong winds increased the threat of falling trees, damaged utility lines and blocked roads.
Paysandú 🙌🏻El río Uruguay! 🇺🇾 📹 Belén Machín. pic.twitter.com/YNj1pkNhdQ
— Matias Clima Meteo 🇺🇾 𝕏 (@AficionadoMeteo) August 7, 2026
Mobility restrictions and storm impacts
The red alert restricted travel and suspended risk-related government activities without affecting employee pay. Essential healthcare, security, emergency and meteorological services continued, while private organisations were urged to limit travel and protect workers. Residents were advised to remain indoors, secure loose objects and avoid trees, power lines and coastal activities.
A 59-year-old rural worker and his horse tragically lost their lives after being hit by lightning near Tupambaé, Cerro Largo. Around 32,000 households lost electricity, while firefighters responded to more than 140 incidents involving damaged roofs, fallen trees and utility poles. Flooding and debris also obstructed several roads.
Graves daños por tormenta en Uruguay. pic.twitter.com/nQxdImx3cx
— Alertageo (@alertarojanot) August 6, 2026
