South America Weather & Natural Hazards Today – Thursday, November 12, 2026

By Paul Harrison | Orbis Weather | November 12, 2026

Regional weather and natural hazards report covering Brazil, Argentina, Chile, Peru, Colombia, Ecuador, Bolivia, Paraguay, Uruguay, Venezuela, Guyana, Suriname and French Guiana.

🌎 South America Weather Overview

South America enters Thursday, November 12, with several significant weather and environmental risks demanding attention, from tropical rainfall across the Amazon Basin to spring thunderstorms in the continent’s southern regions.

Flooding remains a particular concern across parts of the Río de la Plata basin, where recent reports have documented elevated river levels, evacuations and repeated heavy rainfall affecting Uruguay and neighboring countries.

Meanwhile, the developing 2026–27 El Niño event is an important influence on seasonal weather patterns, potentially increasing rainfall across portions of southeastern South America while contributing to drier conditions elsewhere.

Along the Andes, earthquakes, volcanic activity, mountain rainfall and landslides remain important hazards for communities and travelers.

Verification note: A complete set of live national meteorological warnings and observations for November 12 was not available for independent verification during preparation. This report distinguishes documented recent developments from seasonal hazards and conditions requiring monitoring. It should not be interpreted as confirmation of active warnings in every country.

🚨 South America Natural Hazards Summary

These are regional monitoring priorities, not verified active-alert classifications for November 12.

🇺🇾 Uruguay – River Flooding Remains a Major Concern

One of the most consequential recent weather developments in South America has been flooding along the Uruguay River and surrounding drainage basins.

Recent reporting describes evacuations in parts of Uruguay following repeated heavy rainfall and rising river levels.

Flooding has affected communities in the country’s northwest, including areas associated with Salto and Paysandú.

The situation has wider regional implications because the Uruguay and Paraná river systems extend across international borders, linking rainfall and river conditions in Brazil, Paraguay, Argentina and Uruguay.

Recent reports have also described flooding-related disruptions and evacuations in neighboring parts of the basin.

What residents should monitor

River levels can remain elevated even after local rainfall stops because floodwater continues moving downstream.

Communities near rivers should monitor official flood forecasts, reservoir information and evacuation instructions.

Additional heavy rainfall over saturated catchments could worsen flooding, although a new flood peak for November 12 has not been independently confirmed.

Official monitoring: Instituto Uruguayo de Meteorología (INUMET).

🇧🇷 Brazil – Tropical Rainfall and Thunderstorm Risks

Brazil’s vast geography creates several distinct weather patterns during November.

Southeastern Brazil

São Paulo, Rio de Janeiro, Minas Gerais and Espírito Santo are entering a season when rising humidity and daytime heating can support frequent thunderstorms.

Potential hazards include:

• Intense rainfall capable of overwhelming urban drainage.

• Lightning and gusty thunderstorm winds.

• Localized flash flooding and transport disruption.

• Landslides in steep terrain following prolonged rainfall.

Central and Northern Brazil

Across Amazonas, Pará, Mato Grosso and surrounding regions, tropical moisture supports the development of showers and thunderstorms.

The Amazon Basin is particularly sensitive to prolonged rainfall because river levels respond to precipitation across enormous upstream catchments.

Southern Brazil

Rio Grande do Sul, Santa Catarina and Paraná should continue monitoring frontal systems and developing thunderstorms.

Springtime atmospheric instability can support strong wind gusts, hail and localized flooding when favorable conditions develop.

The wider Paraná and Uruguay river basins also deserve attention because rainfall across southern Brazil can influence downstream flood conditions.

Official monitoring: Brazil’s National Institute of Meteorology (INMET).

🇦🇷 Argentina – Severe Spring Thunderstorms and River Conditions

Argentina’s spring season brings increasing temperatures, changing frontal systems and opportunities for organized thunderstorms.

Buenos Aires and Central Argentina

Buenos Aires Province, Córdoba, Santa Fe and Entre Ríos are regions where warm, moist air can interact with passing cold fronts.

Under favorable atmospheric conditions, thunderstorms may produce large hail, damaging winds, frequent lightning and intense rainfall.

No specific severe-weather outbreak for November 12 has been independently confirmed in this report.

Northern Argentina

Misiones, Corrientes, Chaco and Formosa are important areas to monitor for thunderstorms and river flooding.

Recent regional flooding reports have highlighted the vulnerability of communities along the Paraná River and other connected waterways.

Patagonia

Southern Argentina remains exposed to rapidly changing weather, strong winds and colder mountain conditions.

Travelers crossing the Andes should monitor forecasts for wind, visibility and occasional high-elevation snowfall.

Official monitoring: Argentina’s Servicio Meteorológico Nacional (SMN).

🇨🇱 Chile – Mountain Weather, Wildfires and Volcanic Monitoring

Chile stretches from the Atacama Desert to the storm-prone southern Pacific, producing sharply contrasting weather conditions.

Northern Chile

Antofagasta, Tarapacá and Atacama generally experience dry conditions, although unusual mountain rainfall can generate dangerous runoff in normally dry channels.

Central Chile

Santiago, Valparaíso and neighboring regions are approaching the warmer summer season.

Periods of low humidity, dry vegetation and strong winds can increase wildfire danger.

Residents should monitor local fire restrictions and emergency announcements.

Southern Chile

Los Lagos, Aysén and Magallanes remain exposed to Pacific weather systems, strong winds and rapidly changing mountain conditions.

🌋 Volcanic hazards

Chile’s volcanic monitoring network observes numerous potentially active systems, including Villarrica and Nevados de Chillán.

Potential volcanic hazards include ashfall, gas emissions, debris flows and lahars.

The presence of a monitored volcano does not establish that an eruption is occurring.

Official monitoring: SENAPRED and SERNAGEOMIN.

🇵🇪 Peru – Andean Rainfall, Landslides and Seismic Activity

Peru faces contrasting weather between its Pacific coastal desert, the Andes and the Amazonian lowlands.

Lima and the Pacific Coast

Coastal Peru typically experiences relatively limited rainfall compared with its mountainous and rainforest regions.

Marine conditions, coastal fog and temperature variations remain important considerations.

Andes Mountains

Cusco, Puno, Ayacucho and other mountain regions can experience developing rainfall as the Southern Hemisphere wet season approaches.

Steep slopes, narrow valleys and vulnerable mountain roads can increase the consequences of intense rainfall.

Landslides and rockfalls may occur where soils become saturated.

Amazonian Peru

Loreto, Ucayali and Madre de Dios can experience tropical showers and thunderstorms.

Communities near rivers should monitor water levels and rainfall conditions.

Earthquake monitoring

Peru lies along an active tectonic boundary where the Nazca Plate descends beneath the South American Plate.

Earthquake preparedness remains essential, particularly in coastal communities where strong offshore earthquakes may generate tsunami hazards.

Official monitoring: SENAMHI Peru and Instituto Geofísico del Perú.

🇨🇴 Colombia – Heavy Rainfall and Landslide Vulnerability

November is an important rainfall period across much of Colombia.

Bogotá and the Andes

Mountain communities can experience heavy showers, thunderstorms and rapidly changing visibility.

Where rainfall accumulates over several days, saturated soils may increase landslide vulnerability.

Pacific Colombia

The Pacific coastal departments experience some of the highest annual rainfall totals in South America.

Persistent tropical moisture can produce significant rainfall, swollen rivers and localized flooding.

Caribbean Colombia

Cartagena, Barranquilla and Santa Marta should continue monitoring tropical rainfall and coastal marine conditions.

The Atlantic hurricane season officially continues until November 30, although no specific tropical cyclone threat to Colombia has been verified for this report.

Official monitoring: IDEAM Colombia.

🇪🇨 Ecuador – Volcanoes, Earthquakes and Changing Rainfall

Ecuador faces multiple natural hazards because of its position along the Pacific Ring of Fire and its varied tropical and mountain environments.

Quito and the Highlands

Mountain communities can experience rapidly changing temperatures, showers and reduced visibility.

Coastal Ecuador

Rainfall patterns can be influenced by changes in Pacific Ocean temperatures and the development of El Niño.

However, the presence of El Niño does not automatically mean heavy rainfall will occur on a particular day.

🌋 Volcanoes

Important monitored volcanic systems include Cotopaxi, Reventador and Sangay.

Potential hazards include volcanic ash, gas emissions and debris flows.

No new eruption or alert-level change for November 12 is asserted without a verified geological bulletin.

Official monitoring: Instituto Geofísico de Ecuador.

🇧🇴 Bolivia – Tropical Thunderstorms and Highland Weather

Bolivia’s eastern lowlands and western highlands experience markedly different conditions.

Santa Cruz and the Lowlands

Warm, humid weather can support developing showers and thunderstorms.

Periods of intense rainfall can create localized flooding, particularly near rivers and poorly drained urban areas.

La Paz and the Andes

High-altitude communities face cooler temperatures, variable mountain weather and reduced visibility during showers.

Heavy rainfall can increase the risk of landslides along mountain roads and steep slopes.

Official monitoring: SENAMHI Bolivia.

🇵🇾 Paraguay – Thunderstorms and Paraná River Flooding

Paraguay remains an important region to monitor because of its position within the Paraná and Paraguay river systems.

Recent regional reporting has described flooding and evacuations affecting communities along the Paraná River, including areas near Ciudad del Este.

Spring thunderstorms can also bring lightning, heavy rainfall, hail and strong winds.

River conditions depend on rainfall across extensive upstream watersheds, meaning flooding can continue even after storms have moved away.

Official monitoring: Dirección de Meteorología e Hidrología.

🇻🇪 Venezuela and the Guianas – Tropical Rainfall

Venezuela, Guyana, Suriname and French Guiana experience tropical weather patterns influenced by moisture, atmospheric circulation and seasonal rainfall changes.

Venezuela

Caracas and surrounding mountainous areas can face localized flash flooding and landslides during periods of intense rainfall.

Guyana, Suriname and French Guiana

Tropical showers and thunderstorms can produce temporary urban flooding, lightning and poor visibility.

River levels and drainage conditions are especially important following prolonged rainfall.

Residents should follow national meteorological agencies and civil protection services for local warnings.

🌡️ El Niño 2026–27 – A Major Climate Influence

One of the most important factors shaping South America’s seasonal outlook is the strong El Niño event developing across the tropical Pacific.

El Niño involves unusually warm sea-surface temperatures in the central and eastern equatorial Pacific, accompanied by changes in atmospheric circulation.

Climate research published during 2026 has highlighted the potential for an exceptionally strong event.

Its effects are not uniform across South America.

Historically, El Niño has been associated with increased rainfall in parts of southeastern South America and central Chile during particular seasons, while northern South America and portions of the Amazon can experience increased drought risk.

Research also emphasizes that seasonal relationships represent changes in probability, not guarantees of specific local outcomes.

Regional climate implications

The precise effects will depend on the evolution of ocean temperatures, atmospheric circulation and regional weather systems.

🌎 Earthquake Monitoring Across South America

South America’s western margin is one of the world’s most active tectonic regions.

The interaction between the Nazca and South American plates produces frequent earthquakes across Chile, Peru, Ecuador and Colombia.

Earthquake activity is also monitored in parts of Argentina, Bolivia and Venezuela.

Earthquake preparedness

Residents should identify safe shelter locations, secure heavy furniture and maintain emergency supplies.

During strong shaking, drop, cover and hold on.

Coastal residents should follow official tsunami evacuation instructions following a strong or prolonged earthquake.

Verification: No specific November 12 earthquake magnitude, epicenter or tsunami warning has been independently established in this edition.

For confirmed events, consult the USGS Latest Earthquakes Map.

🌋 South America Volcano Monitoring

This is a list of volcanoes requiring ongoing scientific monitoring, not confirmation that each is erupting today.

For official updates, consult national geological agencies and the Smithsonian Global Volcanism Program.

🔥 Wildfire and Air Quality Outlook

As the Southern Hemisphere approaches summer, wildfire risk can increase in areas experiencing warmer temperatures, dry vegetation and strong winds.

Regions to monitor include central Chile, portions of Argentina and seasonally dry areas of Brazil.

Wildfire smoke can travel considerable distances, reducing visibility and affecting air quality far beyond the fire itself.

No specific active wildfire perimeter or air-quality index reading has been verified for November 12 in this report.

🌊 Marine and Coastal Conditions

South America’s Atlantic, Pacific and Caribbean coastlines face different marine hazards.

Pacific Coast: Chile, Peru, Ecuador and Colombia can experience changing swells, strong coastal currents and hazardous surf.

Atlantic Coast: Brazil, Uruguay and Argentina can experience increased wave heights and stronger winds when frontal systems and offshore low-pressure areas develop.

Caribbean Coast: Northern Colombia and Venezuela should monitor tropical showers, thunderstorms and locally hazardous marine conditions.

Fishermen and recreational boaters should consult official marine forecasts before departure.

📅 South America Weather Outlook – Next 72 Hours

Thursday, November 12 – Saturday, November 14, 2026

Forecast limitation: This is a regional hazard-planning outlook, not a verified location-specific numerical forecast. Exact rainfall totals, temperatures, wind speeds and storm timing require current meteorological model guidance and official national forecasts.

🛡️ Safety Advice for Residents and Travelers

• Flooding: Never drive or walk through floodwater. Roads and bridges may be damaged beneath the surface.

• Thunderstorms: Seek substantial indoor shelter when thunder is heard.

• Landslides: Watch for falling rocks, unusual slope movement, new cracks and rapidly rising streams.

• Earthquakes: Drop, cover and hold on. Follow coastal tsunami guidance when applicable.

• Volcanic ash: Follow civil protection instructions and reduce exposure to airborne ash.

• Wildfires: Follow evacuation orders promptly and avoid activities that could ignite dry vegetation.

• Marine hazards: Check official wind, wave and coastal warnings before traveling offshore.

📡 Official Weather and Natural Hazard Sources

Orbis Weather recommends these primary sources for observations, warnings and emergency information.

🔎 How Orbis Weather Prepares This Report

Orbis Weather provides independent regional weather and natural hazard reporting using publicly available meteorological information, scientific research, disaster reporting and official monitoring resources.

Our editorial approach distinguishes between four categories of information:

1. Confirmed events: Developments supported by identifiable reporting or official observations.

2. Official warnings: Alerts issued by authorized meteorological, geological or emergency agencies.

3. Forecast risks: Conditions indicated by meteorological guidance that may develop.

4. Seasonal hazards: Known regional risks that require monitoring but are not necessarily occurring today.

For this November 12 edition, recent regional flooding reports and climate research were reviewed. However, a comprehensive set of current national warning bulletins, numerical forecasts, earthquake reports and volcanic activity updates could not be independently verified.

Consequently, this report does not invent warning levels, rainfall totals, earthquake magnitudes, temperatures or active emergency declarations.

Weather forecasts are subject to change, and local conditions can differ substantially from regional assessments.

Orbis Weather is an independent weather information publisher, not an official warning authority. Readers should prioritize their national meteorological agencies and emergency management services during hazardous events.

🌎 Final Outlook – What South America Should Watch

South America’s weather and natural hazard picture for Thursday, November 12, is shaped by several important concerns.

Recent river flooding in Uruguay and neighboring parts of the Paraná–Uruguay basin highlights the consequences of repeated rainfall across interconnected watersheds.

Brazil, Argentina and Paraguay remain regions to monitor for developing thunderstorms as spring progresses.

Across Colombia, Ecuador and Peru, tropical rainfall and mountain terrain create ongoing flooding and landslide vulnerabilities.

Chile faces a combination of changing mountain weather, volcanic monitoring and increasing seasonal wildfire concerns.

The strong 2026–27 El Niño event adds an important longer-term dimension, with potentially significant consequences for rainfall, drought and river conditions across the continent.

The principal message is preparedness: South America’s natural hazards vary considerably by region, and residents should follow verified local warnings rather than assume continent-wide conditions apply to their communities.

Orbis Weather will continue reporting on severe storms, flooding, earthquakes, volcanoes, wildfires and developing environmental hazards across South America.

South America Weather & Natural Hazards Today is prepared by Paul Harrison for Orbis Weather