October’s storms announced that El Niño has arrived in Southern California.
Now, Southern California is bracing for the impending Super El Niño expected to bring above-average rainfall to the area. The climate pattern is nothing new for residents, but forecasts are pointing to a potentially record-breaking storm season.
Here’s what to know about the upcoming season.
What is El Niño?
El Niño occurs naturally every two to seven years when temperatures in the eastern tropical Pacific Ocean rise at least 0.5 degrees Celsius (0.9 degrees Fahrenheit) above average for several months, according to the National Oceanic and Atmospheric Administration. At the same time, trade winds that usually push warm water from east to west weaken. This leads to a buildup of warm water in the tropical Pacific.
The eastern Pacific begins to exhibit symptoms of El Niño during the summer, when El Niño tends to cause an uptick in hurricane formation in the Pacific, according to the NOAA. This year, the National Hurricane Center has documented above-normal hurricane conditions in the eastern Pacific, with 20 named storms, 10 hurricanes and eight major hurricanes listed as of Nov. 4.
We are getting these big Pacific hurricanes coming
“We are getting these big Pacific hurricanes coming up from tropical areas and impacting our area,” said Dr. Clarissa Anderson, a researcher at Scripps Institution of Oceanography. “That does happen during El Niño events, because we have so much warming in the Pacific, that you’re getting a lot of convection and warm storms that are coming off of that.”
On the other side of the U.S., El Niño has the opposite effect on hurricane season. This season, as of Nov. 4, the National Hurricane Center had documented only 10 named storms, one hurricane and one major hurricane in the North Atlantic — all below-average numbers for that region’s hurricane season.
El Niño events also trigger Kelvin waves — large, slow-moving pulses under the ocean surface that push warm water across the Pacific Ocean and toward North and South American coasts. It takes a few months for a Kelvin wave to cross the ocean, triggering the heightened sea levels and warm waters that hit Southern California coasts, Anderson said.
Anderson said they started seeing a Kelvin wave
Anderson said they started seeing a Kelvin wave in early October, with more on the way in the coming months. Peak El Niño ocean conditions are not expected to hit until December or January, with the Scripps Institution predicting the strongest impacts will strike Southern California from January through April.
El Niño conditions usually last for about nine to 12 months, according to the NOAA, with rainfall associated with the phenomenon usually intensifying during the winter months in Southern California.
What makes this El Niño different?
This year’s El Niño season is classified as a “Super” El Niño because temperatures in tropical Pacific waters have risen a few degrees above the normal El Niño range, Anderson said. El Niño is also converging with other climate phenomena, including a large marine heat wave that started in spring 2025.
That has really created a different situation, where
“That has really created a different situation, where you’ve got a large warming event, and then an El Niño moving on top of that, which is bringing additional warming,” Anderson said. “That’s one of the reasons why you’re hearing a lot about what a Super El Niño of this magnitude could mean for our region now.”
Though Super El Niño conditions mean warmer-than-average waters in the tropical Pacific, it does not necessarily mean a “super” level of rainfall. The 2015-16 Super El Niño was one of the strongest on record, but it did not bring significant rainfall to California.
But forecasting indicates that this season is shaping up to be similar to the strong 1997-98 Super El Niño, which brought record levels of rainfall to California, triggering mudslides and flooding, said Anderson. In 1998, Los Angeles received 27.06 inches of rain, which is the second highest annual rainfall on record in the city since 1950, outranked only by the 29.47 inches documented in 1983 The 1982-83 season was also known as a particularly strong El Niño season
Climate change also threw a curveball into predictions
Climate change also threw a curveball into predictions for this year. This season’s El Niño event is stacked upon already warmer waters in the Pacific believed to be driven by climate change.
This layering effect appeared to contribute to higher — and more prolonged — levels of global rainfall during the 2023-24 El Niño season, said Dr. Chad Thackeray, an assistant researcher at UCLA’s Department of Atmospheric and Oceanic Sciences. Climate change might intensify the rainfall again this season.
“When you factor in projections that 2027 is expected to be the warmest year on record, there’s a pretty high likelihood that we’ll see similar records for this extreme rainfall,” Thackeray said.
How does El Niño affect other parts of the world?
California is just one piece in a larger
California is just one piece in a larger series of events during the El Niño cycle. El Niño’s weakened trade winds lead to less monsoon rainfall from June to September, which has already played out this year as India has seen its fourth lowest rainfall season since 2001 with “severe rainfall deficits,” according to the U.S. Department of Agriculture. Australia and Indonesia also tend to see drier conditions.
Like the southern U.S., South America’s Pacific coast can see heavy rainfall in countries like Peru, Chile and Ecuador. El Niño conditions then typically hit Japan and China, bringing increased rainfall and flooding, according to the Scripps Institution.
While El Niño usually brings a wetter winter to California and the southern U.S., the northern regions of the country tend to see drier conditions The Pacific Northwest will likely see drought conditions and could see heightened wildfire risks, Anderson said
The warm ocean waters are expected to push
The warm ocean waters are expected to push overall global temperatures upward and Anderson said arctic storms should be weakened by El Niño, though atmospheric warming has led to “anomalous” conditions, making predictions tricky.
Thackeray said that El Niño’s effects, combined with climate change, could contribute to another big year for global rainfall.
What are the dangers of Super El Niño?
Rainfall is expected to hit regions across Southern California, but some areas face more dangers than others. Low-lying regions along the coast are a key concern, Anderson said, as the warm El Niño waters lead to “much higher water levels than people are expecting.”
Homes along coastal cliffs could face cliff erosion
Homes along coastal cliffs could face cliff erosion triggered by the waves and rainfall, Anderson said. Coastal cliff collapses from intense wave action could put people in danger.
Fire-impacted areas, ranging from the still-recovering Pacific Palisades to the recent Norte fire in San Clemente, could see intense erosion, debris flows and flooding.
The strength of California’s critical infrastructure has become a central concern heading into the stormy season, especially following an October report from the California State Auditor identifying more than 50 dams across the state that are in poor or unsatisfactory condition. Storms could overwhelm dams and levees, intensifying flooding in high-risk areas.
Across inland regions, roadway, riverbed and canyon areas
Across inland regions, roadway, riverbed and canyon areas pose flooding concerns a spokesperson for the Riverside County Emergency Management Department. Areas of concern in the Inland Empire include Mead Valley, North Shore and Mira Loma in Jurupa Valley
How can you prepare?
To minimize roadway damage and flooding, Caltrans is clearing drainage systems, reinforcing slopes and ensuring that pump stations are ready for heavy rain, said Caltrans spokesperson Lauren Walike. They have also repaired pavement along State Route 60 and State Route 71 to prepare for extreme weather.
Crews across Southern California are also clearing drainage channels of vegetation to create more capacity for water flow.
Reichardt encouraged people to resist the desire
Reichardt encouraged people to resist the desire of wanting “to go and see” large storms and to stay in safe locations and avoid flooded roadways during extreme weather conditions.
For homeowners, clearing rain gutters, trimming branches, ensuring streams are not blocked on private property, and using sandbags in flood-prone areas can help minimize damage.
To stay safe, residents should follow alerts and be aware of where infrastructure might be impacted by storms, Anderson said.
