Record-setting heat and fast-moving wildfires have afflicted large swaths of the Southern Hemisphere as 2026 began, with destructive blazes and extreme temperatures reported from Argentina and Chile to Australia and South Africa. Scientists warn the events reflect the increasing dominance of human-driven warming over natural climate variations, and they say future shifts in Pacific climate patterns could push global temperatures even higher.
In January, a pronounced heat dome settled over Australia and pushed temperatures close to 50 degrees C (122 degrees F). At the same time, intense heat and catastrophic wildfires torched parts of South America, including remote areas of Argentina’s Patagonia, while coastal towns in Chile suffered deadly fires that killed 21 people. South Africa has also reported its worst wildfire activity in years, with fires striking popular tourist destinations and wildlife areas.
These extremes have unfolded even though the world remains under the cooling influence of a weak La Nina, a climate pattern characterized by cooler-than-normal sea surface temperatures in the central and eastern tropical Pacific that began in December 2024. The persistence of record or near-record heat despite this moderating factor leads researchers to conclude that the signal from human-caused climate change is now stronger than natural variability.
"This means the effect of human-caused climate change is overwhelming natural variability," said Theodore Keeping, a climate scientist at Imperial College London and the World Weather Attribution collaboration who studies wildfires and extreme heat. He added that as the climate transitions toward a neutral phase or an El Nino state, the frequency and severity of extreme heat events are likely to be further amplified.
El Nino typically has the opposite effect of La Nina, warming the central and eastern Pacific and raising global temperatures. Forecasts indicate that global temperature for the year is likely to be around 1.46 degrees C (2.6 degrees F) above pre-industrial levels, a projection cited by Adam Scaife, head of long-range prediction at the United Kingdom’s national weather and climate service. If realized, that figure would mark the fourth consecutive year with global temperatures more than 1.4 degrees C (2.5 degrees F) above pre-industrial levels.
Scaife noted that should a strong El Nino develop rapidly in 2026, it remains possible that 2026 could set a new record for the warmest year globally. The World Meteorological Organization has already said the past three years were the warmest on record.
Fires spreading across landscapes and into communities
While many wildfires originate from human activities, fire is also a natural component of numerous ecosystems. Yet prolonged heat, drought and extreme temperatures are changing fire behavior and turning blazes that in the past might have been relatively contained into large, uncontrollable events that cause lasting damage to ecosystems not adapted to such conditions.
Carolina Vera, a meteorologist at the Center for Ocean and Atmospheric Research at the University of Buenos Aires, cited the fires in Argentina’s Los Alerces National Park as an example of this shift. The park, a UNESCO World Heritage site with trees that have lived for more than 3,000 years, was hit by a lightning-caused fire that initially appeared under control. But a concurrent heat wave and strong winds caused the blaze to spread roughly 20 km (12 miles) in a single day, making it the most severe wildfire in that area in two decades. The region has been persistently drought-stricken since 2008, and temperatures in the first half of January ran about 6 degrees C (11 degrees F) above normal.
Vera said these fires once burned out on their own and formed part of the forest’s natural dynamics. "This is an example of how climate change can alter a natural fire, because it appeared to be caused by lightning," she said. The Los Alerces area is remote and contains no towns, but other fires struck more populated zones.
In southern Chile, blazes that began later in January crossed into the greater Concepcion area, the country’s third-largest metropolitan region, destroying hundreds of homes and killing 21 people in coastal communities. The damage in some towns was near-total, and accounts from survivors describe how rapidly flames and embers can overrun evacuation routes when winds intensify.
"Where there’s been the greatest loss of life, it almost always comes down to evacuation being difficult or impossible," Keeping said, noting that strong downslope winds toward coastlines can make escape routes perilous or impassable. He compared the Chilean events to recent catastrophic fires in Los Angeles, Athens and the Hawaiian island of Maui, where high winds and constrained evacuation pathways contributed to heavy civilian casualties.
Local experiences of inferno
Residents of Punta de Parra, a small coastal town in southern Chile ringed by hills and forests, recounted scenes of sudden devastation. About 80% of the town was destroyed, according to local descriptions, and people said they had little time to flee.
Doralisa Silva, 34, recalled learning of a nearby fire the night the blaze reached her town. "Out of nowhere, the forest started burning and all the houses caught fire," she said. Silva and her partner Hermes Barrientos described winds as strong as nearly 70 km per hour (43.5 mph) whipping embers and creating whirlwinds of fire that raced down to the beach and trapped residents. The family, which included a 2-year-old child, found refuge in a central dirt field and spent the night watching their community burn.
Such accounts underscore how quickly conditions can deteriorate when intense winds combine with extreme heat and dry fuels, turning fires into fast-moving events that can overwhelm local capacity to evacuate and protect property.
Wider regional consequences and the long-term picture
Australia recorded its hottest conditions in January, driving the nation’s most severe fires since the destructive 2019-2020 season, during which 33 people died. South Africa is experiencing what officials describe as its worst fire season in a decade, with fires killing wildlife and severely affecting tourist locations such as Mossel Bay and Franschhoek.
Keeping emphasized that the climatic ingredients for extreme wildfires - hot, dry and windy weather - are becoming both stronger and more frequent across diverse regions of the globe. He noted that the Southern Hemisphere has warmed by roughly 0.15 to 0.17 degrees C (0.27 to 0.30 degrees F) per decade since the 1970s, compared with 0.25 to 0.30 degrees C (0.45 to 0.54 degrees F) per decade in the Northern Hemisphere. The slower warming trend in the south is attributed largely to its vast oceans, which absorb heat more slowly, and to meltwater from Antarctica.
Nevertheless, southern land masses are now warming at rates similar to northern land masses. The juxtaposition of warming land and cold meltwater can accentuate certain weather patterns, producing extended heat waves, drought periods or intensified flooding, all of which can influence the likelihood and behavior of wildfire events.
Given these shifting conditions, Keeping and other scientists stress the need for adaptation measures. He recommended that authorities manage vegetation around urban areas, prepare and rehearse evacuation plans, and encourage construction that uses fire-resistant materials to reduce vulnerability. Still, he warned that many large and intense wildfires are effectively unstoppable once they reach a certain scale.
"You actually cannot stop a lot of these really large intense wildfires. They’re simply too big," Keeping said. He added that preventing future worsening of the problem will require serious policy discussions about limiting future climate change.
Economic costs and insurance impacts
Wildfires are producing increasingly large economic losses. A 2026 report by insurance broker Aon estimated global insured wildfire losses at $42 billion in 2025, a sharp increase from the historical annual average of $4 billion between 2000 and 2024. The Los Angeles fires during the prior year were the costliest on record, according to the Aon analysis.
Reinsurer Swiss Re has documented changes in wildfire contributions to insured losses. Before 2015, wildfires accounted for about 1% of global insured losses from natural disasters. That share has grown to around 7% in recent years, and Swiss Re reported that economic losses linked to fires have risen by roughly $170 million per year since 1970.
These trends signal mounting bills for insurers and reinsurers and suggest broader economic exposure in regions afflicted by intense fires. Tourism in affected areas has been hit directly, with destinations suffering losses to infrastructure and wildlife. Property owners and local economies face long recovery periods in the wake of extensive home and community damage.
Outlook
Scientists caution that the ongoing interaction of human-driven warming and natural climate variability could result in even more extreme years ahead, particularly if the Pacific shifts toward El Nino. Forecasts that place this year at about 1.46 degrees C above pre-industrial levels underscore how close recent conditions are to the thresholds discussed in international climate policy.
For communities, insurers and policymakers, the recent spate of fires and heat extremes highlights the urgency of both adapting to current risks and addressing the drivers of longer-term warming to reduce the likelihood of worse outcomes.