This story originally appeared in the Oregon Capital Chronicle and is used with permission.
Warming temperatures at the equator could paradoxically bring the Northwest a wet fall and high winter snowpack, according to climatologists.
The West could be in for “one of the strongest El Niños we’ve had,” Larry O’Neill, Oregon’s state climatologist, said Monday. The ocean and atmospheric weather pattern that occurs every few years and touches all parts of the West typically brings with it warmer and drier temperatures from August through winter, but during a super El Niño — of which there have been only three since 1980 — it does the opposite, bringing greater rain and mountain snowpack.
“The very strong ones don’t follow the typical rule of thumb,” O’Neill said following an online drought and climate outlook meeting hosted by the National Oceanic and Atmospheric Administration.
That could be great for many drought-stricken parts of Oregon and the region, where heat, record low snowpack, depleted reservoirs and low stream levels have caused Gov. Tina Kotek to declare a drought emergency in nearly half the state’s counties. In April, Washington Gov. Bob Ferguson declared a statewide drought emergency for the fourth year in a row, and that same month Idaho Gov. Brad Little declared a statewide drought emergency for the first time in 25 years.
The National Oceanic and Atmospheric Administration earlier this month said El Niño conditions had formed in the Pacific, with a 63% chance of a “very strong” El Niño peaking by the end of the year.
But, O’Neill also cautioned, recent El Niño events and its counterpart La Niña — typically associated with colder temperatures and snow — have become far more unpredictable under rising global temperatures.
“In the last couple years, the La Niñas haven’t really been acting like they usually did. This past year, for instance, we had a weak La Niña, which is supposed to give us a good snow pack, and yet we ended up with our worst snow pack in our recorded history,” he said. “So where exactly this El Niño goes is pretty uncertain.”
If it’s weaker than expected, drought could continue through the winter and spring, exacerbating already low snowpack and water levels. If it is a “very strong” El Niño, depleted reservoirs and mountain snow banks could be refilled and formed, O’Neill said.
Another byproduct of a strong El Niño worth tracking over what’s predicted to be a tough wildfire year: more lightning. O’Neill and his colleagues have been studying decades of lightning patterns in Oregon during El Niño and La Niña events and found that in eastern Oregon there’s a slightly higher prevalence of lightning during an El Niño period.
Record heat
Taken together, August through November of 2025 was the record warmest on average across the Northwest in more than 130 years of recordkeeping. NASA scientists, using NOAA records of global average temperatures dating back to 1880, found that November was the third-warmest on Earth, behind only 2023 and 2024.
This October to May was the second warmest on record for Oregon and Idaho, and the third warmest for Washington. May temperatures across the region were about 4.5 degrees Fahrenheit above normal, and nearly 5 degrees above normal in Oregon. And in the last 60 days, Washington experienced its third warmest June and July on record, Oregon its fifth and Idaho its 15th warmest start to summer.
There’s a 50% to 70% chance that the region will continue to see above normal temperatures from July to September, scientists at the NOAA meeting said.
Low flow
“So not only did we start with below normal snow pack overall, but that snow pack has melted faster than normal as well,” said Karin Bumbaco, Washington’s deputy state climatologist.
Snow in Idaho, western Montana, the Washington Cascades and Snake River Basin melted two to five weeks earlier than normal, and in parts of the Oregon Cascades, mountain snowpack melted two months earlier than normal, Bumbaco said.
In Oregon, this means water reservoirs in Prineville and the Crooked River Basin and Crescent Lake in the Deschutes River Basin are expected to be low or very low by autumn. Crescent Lake is on track to end the season at its lowest level since the drought of the early ’90s, Bumbaco said.
In southern Oregon, some irrigation districts have curtailed junior water rights. In the Klamath Basin, the Klamath Project Drought Response Agency will pay farmers to stop irrigating and leave fields idle to reduce the risk of water shortages.
Oregon is breaking the most records for low streamflow in the region, and it’s expected to get worse in eastern Oregon and southern Idaho during the next four months, according to Bumbaco.
Low power
That’s a problem for the region’s hydropower system, according to Vince Tidwell and Natalie Voisin of the Pacific Northwest National Laboratory. Between 2003 and 2020, the region lost about 300 million megawatt hours of electricity generation from drought alone, Tidwell said, costing the sector about $28 billion.
And despite peak demand for electricity in the region growing by 4.6% since last summer, energy availability has increased by only 1.5%, Voisin said.
“If there was a perfect storm of extreme events, then there is an elevated risk that there could be an energy shortfall,” she said.
