Before this year, the US National Weather Service had never issued a September coastal flood advisory for the San Francisco Bay Area. In the past month, it has had to issue two.
As flood water swallowed intersections and eroded beaches up and down the California coast last week, scientists and emergency managers warned that this is just an early signal of a coming tumultuous winter as an already exceptional El Niño continues to strengthen. It’s been called everything from “super” to “Godzilla”, as forecasters hammer home the message that conditions brewing in the Pacific Ocean could soon climb off the charts, and fuel extreme weather around the world.
Tens of millions could face food insecurity, and global food prices could be pushed higher. Climate scientists have projected that by February, more than 450,000 people around the world could succumb to spikes in temperature linked to the strong El Niño. Yet more deaths will be caused by floods and droughts, wildfires and rain.
More on all this, after this week’s most important reads.
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California is among the places most likely to be hit hard by the climate pattern. Models show a more than 90% chance that this El Niño will be “very strong”, with roughly a 75% chance that it will be historic, according to the latest forecast the US National Oceanic and Atmospheric Administration (Noaa). Severe storms, landslides and destructive high tides are on the menu – and they could happen all at once.
The impacts will be a taste of what’s to come as the world warms. But the effects are also layering on top of conditions fuelled by the human-caused climate crisis. Officials hope that preparations already under way may ready the most vulnerable communities for a more extreme future.
California’s governor, Gavin Newsom, issued a state of emergency on 21 September to mobilise efforts and resources, kicking off a flurry of activity. Preparations are already under way at all levels of government as officials work to secure vital infrastructure, preset response resources and inform the public of the incoming hazards.
Some areas could see supercharged storms and relentless rains. Others face explosive surf, strong currents, and damage to marine ecosystems. The effects of El Niño will add an additional foot of sea level rise in California on top of the 8 to 12in of rise caused by climate change there over the last century, according to state climatologist Michael Anderson.
In recent wildfire burn scars, including the slopes of Big Sur that burned this summer and neighbourhoods devastated by the 2025 firestorm in Los Angeles, there will be higher risks of debris flows. Officials said it typically takes five years for watersheds and hillsides to heal enough to withstand strong storms.
Some adverse conditions fuelled by El Niño are already taking shape. Along with coastal flooding from elevated sea levels and high tides, powerful storms swirling through the Pacific have made for an unusually busy tropical cyclone season in areas unaccustomed to them.
Hawaii is still recovering from a series of deluges and strong winds that flooded roads and buildings, unleashed landslides and toppled trees. Swaths of the Southern California coastline were hammered by massive waves that damaged homes and devoured beaches.
Some spots already hit hard are now working to recover while they prepare for the next round of adverse weather. In Long Beach, just south of Los Angeles, the seawall has been lined with large sandbags to reinforce spots where strong surf has burst through. In Orange County, roughly 690,000 cubic yards (528,000 cubic metres) of sand is being pushed along the coastline. Workers are going door to door in San Diego’s flood zones to help small businesses ready their buildings.
Los Angeles county public works director, Mark Pestrella, said flood control systems are ready and have been optimised during a recent briefing, but the systems are only designed to withstand a so-called “100-year event.” Those have a 1% chance of occurring in any given year, but El Niño could bump those chances higher.
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Meanwhile, LA’s office of emergency management director, Kevin McGowan, is juggling dangers on the other end of the hydrological spectrum: high heat and fire risks that are likely to linger into November.
“We are in the middle of fire season and about to head into a significant heatwave,” McGowan said ahead of a scorching October weekend that smashed several records across Southern California. “People should continue to prepare not just for one hazard – but all hazards.”
While local officials are rushing to get ready, the US is going into the high-risk winter with less capacity to respond or prepare for extreme events, due to cuts in staff and resources issued by the Trump administration, according to experts.
From the beginning of his second term, the president has cracked down on climate science and gutted frontline federal agencies. Deep budget cuts and mass layoffs have reduced the capacity of emergency response agencies, including the Federal Emergency Management Agency (Fema), the agency tasked with coordinating national disaster responses, and the Noaa, considered a global crown jewel for climate science.
“Agencies, particularly Noaa and Fema, were already stretched because we have been seeing more and more extreme weather events,” said Monica Medina, who served as the principal deputy administrator of Noaa during the Obama administration. It’s not yet clear where all the holes may be, but they will become more clear as the needs rise.
“I worry about loss of life and about our inability to be protected at a time when you know we need our government the most,” she said. “If this is a real test,” she added, of a hotter, more precarious future, “we’re going to flunk.”
Read more:
Landslides, flash floods and raging seas: is California ready for the ravages of El Niño?
What is El Niño, what causes it and can we reduce the risks?
A ‘Godzilla-level’ El Niño is causing extreme weather conditions around the world – your questions to our environment writers
