Oregon and Washington Could Face Warmer, Drier Winter as El Niño Nears Historic Strength

Oregon and Washington could be heading into a warmer, drier winter as a strengthening El Niño in the Pacific Ocean has a chance of becoming one of the strongest such events on record.

NOAA Warns El Niño Could Reach Historic Strength

According to the National Oceanic and Atmospheric Administration’s Climate Prediction Center  (CPC), El Niño strengthened further during August, with sea-surface temperature anomalies exceeding 3°C in the eastern equatorial Pacific.

The Climate Prediction Center says there is now a greater than 90% chance of a very strong El Niño during the Northern Hemisphere fall and winter of 2026-27.

It also gives a 75% chance that the October-December event will exceed the strength of previous El Niño events dating back to 1950.

The agency notes, however, that even an unusually strong El Niño does not guarantee particular weather conditions.

Potential Effects in Oregon and Washington

The US Department of Agriculture‘s Northwest Climate Hub says Oregon and Washington typically experience warmer and drier fall and winter conditions during El Niño events.

That can mean less precipitation overall and a greater share of precipitation falling as rain rather than snow.

Reduced mountain snowpack and snowmelt can subsequently decrease runoff and summer water availability, potentially contributing to drought and increased wildfire risk.

Strong El Niño events can also affect Oregon’s coastline, with larger waves and higher sea levels contributing to erosion.

The phenomenon can have consequences beyond weather. The USDA notes that reduced snowmelt and runoff can affect freshwater habitats and salmon fisheries, while warmer ocean temperatures can affect the growth and survival of juvenile salmon and steelhead.

The USDA emphasizes that El Niño increases the likelihood of these conditions but does not guarantee them. Other weather and climate factors also influence conditions across the Northwest.