The Panama Canal, which connects the Atlantic and Pacific oceans, is becoming more vulnerable to both water shortages and excessive water volumes as rainfall patterns grow more variable. Rising temperatures, more intense downpours and longer dry periods are making it harder to manage the water resources of one of the world’s key waterways for global trade.
The canal opened on August 15, 1914, and its first vessel was the American steamship Ancon. The canal’s opening transformed the connection between the Atlantic and Pacific oceans in international maritime transport.
Variability is becoming more prominent than rainfall totals
Steven Paton, director of the Physical Monitoring Program at the Smithsonian Tropical Research Institute, said climate variability had become more pronounced around the Panama Canal in recent years. Paton said temperatures had risen by about 1 degree, particularly at night and especially in areas outside the city.
Paton said some projections for Panama City put the temperature increase at as much as 3 degrees, but noted that these projections had not undergone peer review and that the increase could be linked to the urban heat-island effect. The expert said no statistically significant change had been detected in Panama’s average rainfall, adding that basin rainfall showed approximately 20 percent natural variability over 10-year periods in long-term records.
According to Paton, the main change is occurring in the distribution of rainfall. More intense downpours and longer dry spells are being observed on a daily scale, along with greater variability at seasonal and annual scales.
Dry and wet periods followed one another in 2026
Paton cited 2026 as a striking example of this fluctuation. The January–March period, which made up the first three months of the dry season, was the wettest period in the history of observations. By contrast, the period from April through July was described as the driest ever recorded.
The expert said this was the third severe drought linked to El Niño in 10 years and that dry periods of this scale had never previously occurred at such short intervals. He said the Panama Canal Authority’s uninterrupted 143-year rainfall archive offered a unique data set for examining long-term climate changes in the region.
Drinking water takes priority over canal shipping
Paton stressed that caution was needed when establishing a definitive causal link between climate variability and individual weather events. He explained that a relationship had to be conclusively demonstrated in peer-reviewed publications before climate change could be said to have caused a specific outcome. For this reason, he said he used the more cautious term “climate variability” in his assessments.
Paton said both the population around the Panama Canal and the canal itself needed water, adding that drinking-water supplies were protected by law and that the Panama Canal Authority was required to give priority to this need over maritime transportation. He said the most critical period was the dry season from January through April, noting that water reserves had to be forecast months in advance and that every major El Niño event produced different results.
Transit restrictions were imposed during shortages
Paton said the Panama Canal Authority continued to improve resource management during periods of water scarcity and cited 2015–2016 as an example. He said restrictions on vessel sizes and the number of transits were introduced in June 2015, and that although the decision caused revenue losses, it helped prevent a severe water shortage during the 2016 dry season.
Paton said changes in rainfall patterns were also affecting forests in the canal basin, noting a significant increase in the number of woody vines and saying that their causes and possible consequences were being investigated. According to research by the Smithsonian Institution, forests act like a giant sponge, storing water during the rainy season and releasing it gradually during the dry season. Paton said disruption of this system could affect the canal’s access to water.
Paton said Panama’s central government and the Panama Canal Authority had developed laws and policies to protect and restore forests in and around the canal basin. He said work was being carried out on native tree species and planting methods suited to forest restoration.
Long-term monitoring supports adaptation decisions
Paton said scientific monitoring made it possible to identify environmental changes early and develop adaptation strategies in time. He noted that people might have difficulty noticing changes that emerge over the long term, adding that regular measurements made developments that could otherwise be overlooked visible through data.
The expert said scientific data gave decision-makers a basis for action and helped civil-society organizations assess public policies. He stressed that long-term records were necessary to distinguish between climate changes and natural cycles.
Paton said rainfall in the canal basin had declined for 10 to 20 years in the early 1990s. Although this raised concerns that the canal would run out of water, he said the decline was later understood to be part of the natural rainfall cycle as more data were collected. Paton said strong El Niño events had increased over the past 30 years, but added that existing data were not yet sufficient to say this was caused by global warming.
Excessive rainfall is as serious a threat as water shortages
Paton said the greatest climate risk for the Panama Canal in the coming decades was increasing variability in rainfall patterns, stressing that the danger was not limited to water shortages. He said a record amount of rain fell in the canal basin within 48 hours in 2010, and that the resulting water volume nearly exceeded the canal’s carrying capacity.
Paton said canal managers had to ensure sufficient water during dry periods while also controlling excessive water volumes during heavy rainfall. He added that population growth and rising demand for drinking water would increase pressure on resources. The expert said population growth and water consumption needed to be modeled together for the coming decades.
