In June, the National Oceanic and Atmospheric Administration’s Climate Prediction Center declared that an El Niño had developed in the Pacific and was expected to strengthen. The agency now puts the odds of a very strong El Niño between November 2026 and January 2027 at 90%. Already, this El Niño is forecast to be one of the strongest on record, and it will continue to intensify through the rest of the year. For the Pacific Northwest, that forecast carries real consequences for our marine and freshwater ecosystems, for the coastal communities that depend on them, and especially for salmon and steelhead.
The economic stakes are not hypothetical. Following the 2015-16 El Niño, a toxic algal bloom forced the closure of the recreational razor clam fishery on the Washington and Oregon coasts, and the Washington Department of Fish and Wildlife estimated the closure cost the two states roughly $22 million in lost tourism spending. When ocean conditions shift, so do the seasons, the businesses and the towns built around them.
El Niño is the warm phase of the El Niño-Southern Oscillation, or ENSO, defined by warmer-than-average sea surface temperatures in the central and eastern Pacific and occurring every two to seven years. On land, its effects on the Northwest are most evident in winter. For Idaho, Oregon and Washington, fall and winter tend to be warmer and drier during El Niño, which for steelhead country means less overall precipitation, more of it falling as rain rather than snow, reduced runoff and summer water availability, and heightened drought and wildfire risk.
The bigger threat for fish is in the ocean. Past El Niño events have been associated with marine heat waves that push cold-water species northward or deeper and move through the food chain from plankton to top predators. The U.S. Department of Agriculture notes directly that the growth and survival of juvenile salmon and steelhead are affected by warm ocean temperatures. When marine heat waves persist into summer, they may also affect older salmon. In Oregon and Washington specifically, reduced snowmelt and runoff during El Niño often harm freshwater habitats and contribute to declines in salmon and steelhead fisheries. Both the freshwater and marine sides of the steelhead life cycle are squeezed at once.
Climate change compounds the picture. There is broad scientific agreement that strong El Niño events could become more frequent as the planet warms, and that a warming ocean amplifies the marine heat waves that accompany them. What scientists are still working out is how much climate change has already shaped past ENSO events. Either way, the direction is clear: A warmer baseline ocean means each El Niño starts from a higher floor, with more heat to push into the ecosystems our fish depend on.
The early warning we have wouldn’t be possible without NOAA. Ocean and ecosystem monitoring and reporting are critical for understanding this phenomenon and its impacts on our fisheries and their habitats, and NOAA’s diverse array of programs supplies that information. The Climate Prediction Center, ocean-observing buoy networks, marine heat wave monitoring and ecosystem surveys are what allow scientists, managers and advocates to see events like this El Niño coming, understand the impacts, and respond before the damage compounds. NOAA Fisheries also drives the stock assessments, ocean condition tracking and recovery science that Pacific Northwest fish depend on. When that monitoring infrastructure is underfunded or scaled back, we lose the capacity to anticipate marine heat waves, forecast drought and low-flow years, and make sound management decisions in real time. NOAA’s capacity to do this work is not an abstract budget question; it is directly tied to whether we can keep watching over the ocean and freshwater conditions that determine wild steelhead survival.
This winter’s predicted warmer, drier conditions and elevated marine-heatwave risk add another stressor to already-imperiled wild steelhead and the marine fish that share their waters, reinforcing why habitat resilience, cold-water refugia and the science agencies that monitor these threats matter more than ever.
