Argentina's National Weather Service (SMN) has issued orange and yellow alerts for severe storms, torrential rain, hail, and intense winds affecting several provinces on Tuesday, August 18, 2026. The most critical zone is central Entre Ríos, where up to 100 mm of rain is expected. Additional warnings cover snowfall, Zonda wind, and extreme cold in other regions.

⚠️ Severe Weather Alert: What You Need to Know

The Servicio Meteorológico Nacional (SMN)—Argentina's official weather service—has issued orange and yellow alerts for Tuesday, August 18, 2026. These warnings cover strong storms, heavy rainfall, hail, intense winds, and even extreme cold across the country. The most affected area is the central region of Entre Ríos province, where an orange alert is in effect.

Key data: Forecasts predict accumulated rainfall of 80 to 100 mm in the orange alert zone, with isolated higher amounts possible.

Alert Breakdown by Region

Alert LevelPhenomenonProvincesDetails
OrangeSevere stormsCentral Entre RíosIntermittent locally heavy rain, intense gusts, hail, and lightning. Accumulation: 80–100 mm.
YellowStormsSouthern Entre Ríos, Corrientes, Chaco, and Santa FeVaried intensity rain, localized hail, and gusts. Accumulation: 40–60 mm.
YellowStrong windsCatamarca, Chubut, San Juan, Tucumán, Santa Cruz, Salta, Jujuy, Tierra del FuegoWind speeds of 60–80 km/h, with gusts possibly exceeding 120 km/h.
YellowSnowfallMountain zone of Santa CruzAccumulated snow of 10–30 cm, possibly higher in isolated spots.
YellowZonda windPart of JujuyWinds of 30–45 km/h with gusts above 70 km/h. Reduced visibility and low humidity.
YellowExtreme coldNeuquén and MendozaDangerous temperatures for at-risk groups, with mild to moderate health impact.

River Levels Rising in Gualeguaychú

In the city of Gualeguaychú (Entre Ríos), the river's rise has accelerated. According to local authorities, the level reached 3.29 meters at the city port and 3.14 meters at the river mouth (Boca) as of 7:00 AM on Tuesday. The water is just 20 cm below the alert level and 50 cm below the evacuation threshold.

Measurements showed a steady increase between Monday noon and 8 PM: at the port, the river went from 2.29 to 2.89 meters; at the Boca, from 2.21 to 2.78 meters. The National Water Institute (INA) warns of a possible further rise starting Wednesday due to tidal effects, with a risk of approaching the alert level.

📊 Gualeguaychú River Levels (Tuesday 08/18, 7:00 AM)

  • Port Gualeguaychú: 3.29 m
  • River mouth: 3.14 m
  • Alert level: 3.50 m (approx.)
  • Evacuation level: 3.80 m (approx.)
  • Rain accumulated by 9 AM: 42 mm

Emergency contacts in Gualeguaychú: Call 103 (civil defense) or 3446 628885 for assistance.

Safety Recommendations from SMN

  • Avoid going outside during the storm
  • Do not take out trash; clear drains and gutters
  • Unplug appliances and cut off power if water enters your home
  • Close and stay away from doors and windows
  • Secure or remove objects that could be blown away
  • ✅ If outdoors, seek immediate shelter in a building, house, or closed vehicle

Weather in the Buenos Aires Metropolitan Area (AMBA)

In Buenos Aires City, the forecast high is 13°C and low 7°C, with cloudy skies throughout the day and low chances of rain. In the province of Buenos Aires, temperatures will reach a high of 17°C and a low of 10°C.

The Special Report on Significant Phenomena from the National Alert and Emergency Monitoring System (issued on August 14) had already predicted intermittent rains in the Littoral and central region, with accumulations possibly exceeding 100 mm per day in Entre Ríos.

Expected Temperatures for Tuesday, August 18

ProvinceMaxMin
Catamarca15°C8°C
Chaco15°C12°C
Chubut17°C1°C
Córdoba15°C7°C
Corrientes15°C12°C
Entre Ríos12°C9°C
Formosa18°C14°C
Jujuy11°C8°C
La Pampa15°C-1°C
La Rioja18°C8°C
Mendoza15°C6°C
Misiones27°C20°C
Neuquén15°C0°C
Río Negro15°C3°C
Salta11°C6°C
San Juan17°C6°C
San Luis17°C4°C
Santa Cruz9°C3°C
Santa Fe12°C9°C
Santiago del Estero16°C10°C
Tierra del Fuego7°C2°C
Tucumán12°C10°C

Sources: MinutoUno · La Nación · R2820 · Municipality of Gualeguaychú · El Cronista