On the night of February 18 into the early hours of February 19, 2023, one of the most catastrophic natural disasters in Brazilian history unfolded along the northern coast of São Paulo state. The timing could not have been worse: the country was in the middle of its beloved Carnival holiday weekend, when millions of Brazilians travel, celebrate, and gather in coastal towns. Instead of festivities, the region would endure a nightmare of mud, destruction, and grief that would take weeks to fully comprehend.
The meteorological conditions that produced the disaster were extraordinary by any global standard. A persistent area of low pressure positioned just off the Brazilian coast generated a powerful onshore flow, drawing warm, moisture-laden air from the Atlantic directly into the coastal mountains of São Paulo state. As this moist air was forced upward by the terrain in a process known as orographic lifting, it cooled rapidly and released staggering quantities of rain. The mountains essentially acted as a giant engine, wringing every drop of moisture from the incoming air masses and dumping it on the narrow coastal strip below.
The rainfall totals recorded over a single 24-hour period shattered previous records. In Bertioga, a municipality just outside São Sebastião, instruments registered 682 millimeters of rain — the equivalent of more than 26 inches — in a single day. This surpassed the previous national 24-hour record of 530 millimeters, which had been set in Petrópolis in February 2022 and had itself caused deadly flooding. Meteorologists at MetSul Meteorologia noted that the Bertioga figure could rank among the highest non-tropical cyclone rainfall totals ever recorded anywhere in the world. São Sebastião itself received 626 millimeters in the same window. Guarujá logged 395 millimeters, Ilhabela recorded 337 millimeters, and Ubatuba measured 335 millimeters — figures that would each, under normal circumstances, represent months of accumulated rainfall.
The consequences of such extreme precipitation were swift and merciless. The saturated hillsides surrounding the coastal communities gave way in a cascade of landslides and mudslides that roared down onto homes, roads, and neighborhoods with little warning. São Sebastião bore the brunt of the destruction. The city, perched between steep mountains and the sea, had little natural buffer against the flows of earth and debris that swept down from the slopes above. Entire neighborhoods were buried or swept away in minutes. At least 50 homes were completely destroyed, and the scale of the damage quickly overwhelmed local emergency services.
By February 21, authorities had confirmed 44 deaths, with 43 of them concentrated in São Sebastião alone. One additional fatality was recorded in Ubatuba. As rescue teams continued to comb through the mud and rubble in the following days, the death toll climbed steadily. By February 26, the confirmed number of deaths reached 65, with 64 of those in São Sebastião. At least 24 people suffered injuries, six of them critically. Dozens more remained unaccounted for, their fates uncertain as searchers worked through thick layers of debris. At least 2,496 people were left displaced or homeless, their lives upended in a matter of hours.
The infrastructure of the region was also severely damaged. The Rio-Santos highway, the main coastal artery linking São Paulo's northern coast to the state of Rio de Janeiro, suffered extensive destruction, with numerous landslides either burying stretches of the road or carrying sections of it away entirely. A secondary road connecting the city of Santos with Bertioga was blocked off. When additional rains fell on February 21, new landslides struck the community of Juqueí, forcing another 80 people to flee their homes. On February 18, with winds exceeding 55 kilometers per hour and waves surging above one meter, the Port of Santos was closed as a precautionary measure.
Search and rescue efforts mobilized rapidly despite the treacherous conditions. Local emergency management agencies dispatched more than 100 firefighters in the initial response. By February 21, over 600 personnel were on the ground, drawn from the São Paulo state government, the Brazilian Army, the Federal Police, the municipal government of São Sebastião, and scores of volunteers. Among the scenes that captured the nation's attention was the rescue of a two-year-old child and a woman in the middle of giving birth, both pulled alive from what rescuers described as a sea of mud. By February 21, rescue teams had also distributed 7.5 tons of relief goods — food, water, and hygiene kits — to affected communities. Some aid convoys were hampered by looting of trucks carrying donations, adding a grim dimension to the crisis.
The official response escalated quickly at the highest levels of government. On February 20, Governor Tarcísio de Freitas declared a state of emergency for five affected cities. A 180-day state of calamity was subsequently declared for the state of São Paulo, unlocking additional resources and legal powers for the relief operation. Brazilian President Luiz Inácio Lula da Silva visited the devastated areas in person, touring São Sebastião and pledging that the city would be rebuilt in safer locations. He urged those living on the hillsides to relocate, acknowledging that the pattern of informal settlements clinging to steep slopes had made communities far more vulnerable to exactly this kind of disaster.
Military and medical support arrived from the sea. On February 22, the Brazilian Navy ship NAM Atlântico set sail from the Rio de Janeiro Navy Arsenal carrying a field hospital. The vessel arrived at the port of São Sebastião on February 23, bearing 28 medical specialists including surgeons, dentists, and orthopedists, along with 180 marines equipped with heavy machinery to assist in the search and rescue operation. The field hospital had the capacity to be expanded to accommodate up to 300 patients. As Carnival festivities were cancelled across Bertioga, Ilhabela, São Sebastião, and Ubatuba, the region that had expected to celebrate instead settled into the somber work of recovery.
The 2023 São Paulo coastal disaster drew renewed attention to the deep vulnerabilities of Brazilian cities built on or near unstable hillsides. For decades, demographic pressures and inadequate urban planning had pushed low-income communities onto mountainous terrain unsuitable for dense habitation. Each major rain event peeled back the same layers of risk. Climate scientists noted that warming ocean temperatures and shifting atmospheric patterns were increasing the frequency and intensity of extreme rainfall events in southeastern Brazil. The disaster of February 2023 was not only a humanitarian tragedy but a warning — a signal that without fundamental changes in land use policy, early warning systems, and climate adaptation, the cycle of destruction would inevitably repeat.
