From Christmas Currents To Climate Pattern: How El Niño Got Its Name
LOS ANGELES — Southern California is supposed to be cooling down by now.
Instead, the city is sweltering through an October heatwave, with temperatures soaring into the triple digits and an extreme heat warning in effect across much of the region. Downtown Los Angeles recently reached 104 degrees, breaking an October temperature record set more than seven decades ago.
The heat is hard to miss. It lingers into the night, turns sidewalks and asphalt into radiators and makes the idea of autumn feel far away. And while the heatwave itself is being driven by a stubborn area of high pressure over the West, it arrives with a reminder of how deeply connected Southern California is to conditions far beyond its borders.
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Thousands of miles south and west, the Pacific Ocean can help shape the weather experienced across the Americas. One of the most powerful examples is El Niño, a recurring climate pattern that begins with changes in the tropical Pacific but can influence temperatures, rainfall and storms far from the ocean where it originates.
Long before scientists began tracking ocean temperatures with satellites, buoys and computer models, fishermen along the Pacific coast were watching the ocean for signs of change. They noticed that every few years, waters that were normally cool would become unusually warm. At the same time, the amount of fish that were caught declined sharply, affecting communities whose livelihoods depended on the sea.
The unusual warming often appeared around Christmas. For the fishermen of coastal Peru and Ecuador, that timing gave the climate phenomenon a name with a distinctly religious connection: El Niño. Spanish for “the boy” or (in its religious context a reference to the baby Jesus), El Niño has affected the climate for millions and millions of people throughout the Americas.
‘Dangerous weather’
National Weather Service head meteorologist Dr. Ariel Cohen said El Niño is “not a storm” — but a broader weather pattern that shapes an entire season.
“Very strong El Niño events increase the odds of dangerous weather and coastal conditions, including flash floods, burn scar debris flows, severe thunderstorms with damaging winds and tornadoes, coastal flooding, beach erosion and dangerous rip currents,” he said. “However, please notice, I said ‘increase the odds’ — a strong El Niño shifts probabilities, it does not determine outcomes.”
Indeed, El Niño is one of the planet’s most closely watched climate phenomena. It is the warm phase of the El Niño-Southern Oscillation (ENSO), a recurring pattern involving the tropical Pacific Ocean and atmosphere. NOAA describes El Niño as a period when surface waters in the central and eastern equatorial Pacific become warmer than average, accompanied by changes in the trade winds and atmospheric circulation.
But the story behind its name begins not in a lab, but with the observations of people who made their living at sea.
The warm ocean current traditionally appeared near the Christmas season. Fishermen therefore referred to the seasonal warming as El Niño. NOAA’s Climate Prediction Center notes that the term was originally used for a seasonal warming of coastal waters before it came to describe the much larger climate phenomenon scientists recognize today.
That religious connection is important because the name was not originally a scientific classification. It was a practical description of something fishermen repeatedly observed in their environment.
There is also some uncertainty about the exact historical timeline. It is widely believed that the whether phenomenon was recognized and named in the 1600s, although some believe it occurred much later. An early recorded mention of the term in a climate context occurred in 1892 when Captain Camilo Carrillo reported to the geographical society congress in Lima that Peruvian sailors named the warm, south-flowing current after the baby Jesus.
Regardless, El Niño weakens trade winds, pushes warm Pacific water eastward, and shifts the jet stream, creating distinct weather patterns across the Americas. As a result, there is more rain and potential hurricane activity in the Pacific.
Under normal conditions, trade winds generally push warm surface water westward across the tropical Pacific. Along the coast of South America, this circulation helps bring colder, nutrient-rich water from deeper in the ocean toward the surface. That process — called upwelling — supports productive marine ecosystems and fisheries.
Those changes do not remain confined to the Pacific. Because the ocean and atmosphere are closely connected, El Niño can alter rainfall, temperatures and storm patterns thousands of miles away. Its effects can influence agriculture, fisheries, drought, flooding and wildfire conditions in different parts of the world.
Churches to the rescue
Faith-based groups have been involved in trying to mitigate the effects of El Niño by bringing attention to climate change. In June, a study warned that American faith communities are largely unprepared to help their members cope emotionally with the accelerating climate crisis.
The report, “Unprepared for Eco-Grief: Study Shows Spiritual Infrastructure Gap in U.S. Mainline Protestant Churches,” a publication from the EcoPreacher Initiative, found that nearly half of active church members surveyed reported feeling anxiety or dread about climate change (47%).
One of the study’s most significant findings is a notable perception gap between clergy and their congregations. While 80% of church lay leaders cite concern for future generations as a major motivator for climate action, only 64% of their ministers perceived this to be the case for their congregants.
Many churches in the U.S. have come to the rescue. Some have turned their houses of worship and other properties and converted them into cooling centers during heatwaves.
The Rev. Sylvia Harris of Wesley United Methodist Church in Phoenix, Arizona, was an early adopter. Harris turned a closed preschool in 2023 into a cooling and respite center in the city’s south mountain area, helping 700 people in the process.
“What we have found is the more that we reach out and make known what we’re doing,” Harris said, “the more God shows up to provide in the spaces and places that we would not have been able to do this otherwise.”
Clemente Lisi serves as executive editor at Religion Unplugged.