The sea level in La Paz Bay reached its highest point since monitoring began in 1993, according to data from CICESE, Mexico’s Center for Scientific Research and Higher Education in Ensenada. The updated record, extending through August 26, 2026, shows a cumulative rise of 9.2 centimeters over 33 years—a rate of 2.8 millimeters per year.
“It is the highest maximum since we have records,” said Armando Trasviña Castro, a researcher with CICESE’s Tropical Oceanography Group, during a recent public presentation on El Niño 2026 in La Paz.
The rising trend is not uniform. Seasonal variation causes the ocean to swell during summer and recede in winter, while major El Niño episodes—in 1997–1998, 2015–2016, 2023, and now 2026—push the water higher still. El Niño warms the upper ocean, and warmer water expands. “Cold water contracts, warm water expands,” Trasviña explained.
When High Water Meets High Tide
The CICESE tide gauge records the average sea level, but it does not account for daily tidal cycles driven by the gravitational pull of the moon and sun. When an elevated sea level coincides with a high astronomical tide, the water can reach areas normally left dry.
Trasviña’s presentation documented two recent examples: seawater reached the malecón in downtown La Paz on August 1, 2023, and again on August 27, 2026. Both events occurred when the elevated baseline met a peak tide.
Storm surge and ocean swell add further layers of risk. Trasviña clarified the difference: swell refers to waves reaching shore, while storm surge happens when cyclone winds push and pile water toward land. Either can amplify the effect of an already elevated sea level.
Visible Changes Along the Coast
Beyond the malecón, the presentation showed flooding and erosion across the region. On August 27, a localized storm system known as a “torito” struck Cabo Pulmo. Days later, on September 2, floodwaters roared down the Quelele arroyo into La Paz Bay.
Arroyo runoff delivers freshwater and nutrients to the bay, but it also carries plastics, trash and contaminated water from upstream development—temporarily altering coastal conditions.
On September 12, satellite imagery captured three arroyo mouths opening simultaneously near Rancho Ecológico La Duna, north of the city. Ground-level photos documented water flow and erosion across the terrain. Analysis of the previous ten years of imagery found no other instance of all three openings breaching at once.
Trasviña summarized three El Niño–linked disruptions observed in 2026: warming of the upper ocean, the sea-level peak, and increased freshwater discharge from arroyos into coastal waters.
What Waterfront Properties Should Watch
The data does not forecast flooding at a given address, but it does set the stage. Property owners, malecón businesses and coastal developers now know the baseline is higher than it has been in three decades. When that baseline meets a king tide, a swell event or storm surge, the water will reach farther inland than historical patterns suggest.
CICESE and partner institutions—including academic groups, NGOs and fishing cooperatives—have been expanding monitoring efforts since 2024, measuring temperature, sea level, oxygen and currents across the bay. “The academic part is one thing, but interpreting the climate is up to all of us,” Trasviña said.
Residents and businesses in low-lying coastal zones should track tide schedules during periods of elevated sea level, particularly in late summer and early fall when seasonal warming peaks. Malecón vendors, waterfront restaurants and marina operators have already seen what a high tide looks like when the ocean starts 9 centimeters higher than it did in 1993.
For now, the 2026 record stands as the new benchmark—and a reminder that the next high tide may not behave like the last one.
Source Note: This story is based on original reporting by El Sudcaliforniano. It has been independently rewritten and adapted by the Gringo Gazette for our English-speaking readers, with additional context where appropriate.
