El Niño 2026–27 in Brazil: Heat, Flooding, Wildfires and Workplace Risks

Direct answer: what should companies in Brazil do now?

El Niño is not a stand-alone occupational hazard. It can change the environmental conditions in which work takes place and aggravate known exposures: heat, smoke, low humidity, heavy rain, flooding, instability, lightning and wildfires.

Companies should identify weather-sensitive operations, monitor official sources, review stop-and-return criteria and test whether controls, communication and emergency resources remain adequate. This does not mean adding “El Niño” automatically to every Brazilian Occupational Risk Management Program (PGR); it means making the PGR reflect real work.

What official bulletins said on 31 August 2026

On 13 August, NOAA's Climate Prediction Center said El Niño was strengthening and assigned a greater than 90% chance to a very strong event during Northern Hemisphere fall and winter 2026–27. The July Niño-3.4 value was +1.4°C.

For October–December 2026, NOAA calculated a 69% chance of a three-month RONI value of +2.5°C or more, which would exceed earlier events in the record dating to 1950 under that criterion. Brazil's INMET highlighted the high probability of a very strong event during the SON, OND and NDJ seasons.

These are probabilities based on the models and observations available on the evidence date. They do not guarantee the final strength or a disaster at a particular location. NOAA's next monthly discussion was scheduled for 10 September 2026.

A very strong event does not guarantee a very strong disaster

Brazil's Cemaden stresses that El Niño changes probabilities of rainfall, drought and temperature but does not create a disaster on its own. Severe outcomes arise from the interaction of hazard, exposure and vulnerability.

Oceanic intensity may increase the probability of impacts consistent with El Niño, but it does not determine their exact location or magnitude. A company therefore needs local alerts and site conditions, not a seasonal headline alone.

Regional tendencies in Brazil—not regional certainties

Brazil's Ministry of Health used different regional scenarios in its August preparedness plan. Other oceanic and atmospheric systems continue to matter, especially the tropical Atlantic and the Intertropical Convergence Zone in the Northeast.

Occupational heat: a weather-app temperature is not an exposure assessment

Air temperature alone is not occupational heat exposure. IBUTG—the Brazilian acronym for WBGT, Wet Bulb Globe Temperature—represents components of the thermal environment, while assessment also considers metabolic rate, duration, clothing, acclimatisation and work organisation.

Two workers under the same air temperature may have different physiological loads when one is seated and the other performs heavy work. This is why the article does not invent a universal rule such as stopping all work above 35°C.

The ILO estimates globally that 2.41 billion workers are exposed to excessive heat each year and attributes 22.85 million occupational injuries and 18,970 work-related deaths annually to excessive heat. These are global estimates, not Brazilian statistics.

Brazil's NR-15 versus NR-9: a critical distinction

Annex 3 of Brazil's NR-15 establishes criteria for the Brazilian regulatory characterization of unhealthy working conditions for additional compensation where heat exposure occurs indoors or with an artificial heat source. It states that it does not apply to outdoor activities without an artificial heat source.

That exclusion does not mean natural heat requires no prevention. Annex III of Brazil's NR-9 addresses assessment and prevention of occupational heat exposure when the agent is identified in the PGR, and applies wherever such exposure exists.

Compensation characterization and prevention are related but distinct questions. International readers should not treat the Brazilian concept of insalubridade as equivalent to a legal category in their own country.

What the 2026 NR-9 text supports

Brazil's NR-9 requires measures so occupational heat does not cause adverse health effects. Depending on the assessment, controls may include cool drinking water, encouraging intake, scheduling heavier work in milder thermal periods, alternating higher- and lower-exposure operations and thermal recovery in milder locations.

The text also addresses acclimatisation, coordination with the Brazilian occupational medical programme (PCMSO) and a heat-emergency procedure. For certain outdoor activities without artificial sources, the 2026 wording allows use of a Fundacentro tool to support WBGT estimation.

These provisions do not create generic breaks or a single temperature limit. Metabolic rate and representative exposure conditions remain central.

Wildfire smoke and air quality

Drought and heat may favour fire conditions in some regions, but El Niño does not guarantee wildfire. When smoke occurs, fine particulate matter—PM2.5—can penetrate deeply into the respiratory system and aggravate respiratory and cardiovascular conditions.

Agricultural workers, drivers, construction crews, power and telecom teams, couriers and logistics workers may be exposed even when a fire is outside company property. Air quality can become an operational decision variable.

Control should not begin with a universal respirator claim. Organisations should use reliable monitoring, characterise exposure, reduce time in the plume, change the task and implement suitable respiratory protection within a proper programme when necessary.

Heavy rain changes risk before flooding begins

Rain changes friction, visibility, soil stability and access before water enters a facility. Excavations, slopes, scaffolds, heavy equipment, lifting, electrical installations and emergency routes can lose the conditions assessed at shift start.

Inspection and stop-work criteria should be defined before critical weather. A risk assessment completed on dry ground does not remain automatically valid after significant rainfall.

Work at height, wind, rain and lightning

Brazil's NR-35 requires adverse weather conditions to be considered in the risk analysis for work at height. Monitoring, stop authority, communication, shelter and return checks should be planned before the task begins.

This article does not invent a universal lightning distance or wind-speed limit. Criteria depend on the task, equipment, manufacturer information, site and applicable rules.

Flood risk continues after the water recedes

During a flood there may be drowning, current, collision, electrical, fall and instability hazards. Afterwards, mud, biological contamination, sharp objects, dispersed chemicals, animals, structural damage and demanding cleanup remain.

Safe return requires inspection, energy isolation, structural and contamination assessment, and organised cleanup. “The water has gone down” is not a release criterion.

Does El Niño automatically require a PGR revision?

No. A company should determine whether associated conditions change hazards, exposure, schedules, procedures, work organisation or plausible emergencies.

Brazil's NR-1 requires risk reassessment when changes in environments, processes, conditions, procedures or organisation introduce new risks or modify existing ones. Climate information is an input to examine real work; it does not replace risk assessment.

Emergency preparedness and drills

Brazil's NR-1 requires procedures consistent with the risks and circumstances of the activities, including resources and responsibilities for first aid, referral and evacuation. It also requires drills as provided in the procedure and evidence when they are performed.

An external flood is not automatically a ‘major emergency’ under the NR-1 definition. Climate events can nevertheless reach facilities and trigger or worsen process-related scenarios, such as fire, chemical release, loss of power, isolation or structural compromise.

Why this matters for companies operating in Brazil

Multinational and local organisations need to combine official climate monitoring, Brazilian occupational risk management, protection of outdoor workers, emergency preparedness and operational continuity.

Water or power shortages, blocked roads, smoke, unavailable suppliers, worker access and facility damage can interrupt operations without directly injuring anyone. Resilience means protecting people while preserving only what can be operated safely.

Company readiness checklist

Use these questions to guide a site-specific review.

• Which operations depend on weather or access?
• Which groups work outdoors or in heat-accumulating areas?
• Has occupational heat been assessed representatively?
• Are water, acclimatisation and thermal recovery adequate?
• Who monitors official warnings and who can stop work?
• Do height, excavation, electrical and lifting jobs have weather-related hold points?
• Are facilities or escape routes exposed to flooding?
• Does return after rain, flooding or smoke require formal inspection?
• Do emergency exercises test communication and contractor interfaces?
• Are critical water, power, logistics and suppliers backed up?

Conclusion: a forecast creates time to act

Climate outlooks cannot predict every disaster, but they provide time to identify vulnerability and strengthen controls before critical conditions develop.

Climate risk begins before the disaster. When heat, rainfall, smoke or access changes, organisations must ask again whether the same task remains safe and whether people know how to stop and return.