Salem, OR – Oregon is bracing for a winter that could feel colder than normal, as the 2025-26 preliminary outlook from the National Weather Service (NWS) highlights an increased risk of below-average temperatures across much of the state.
According to the NWS Climate Prediction Center, weak La Niña conditions are developing this fall, expected to transition toward neutral mid-winter. Historically, La Niña winters often bring more Arctic air into the Pacific Northwest, paired with frequent Pacific storm systems. For Oregon, that usually means chillier conditions statewide and heavier snow in the Cascades.
Meteorologists caution that the forecast is preliminary and subject to change. Short-term atmospheric drivers such as the Arctic Oscillation (AO) and Madden-Julian Oscillation (MJO) can influence how much cold air reaches the state, as well as when storms track inland.
The early signal suggests:
- Colder-than-normal conditions statewide. Western Oregon, including Portland, Eugene, and Medford, may see more frequent frosts and chilly daytime highs. Eastern Oregon, including Bend, Pendleton, and Baker City, could face prolonged stretches of freezing temperatures.
- Snowier mountains. The Cascades, including Mount Hood, Willamette Pass, and Crater Lake, are likely to see above-average snowfall, improving ski conditions but raising avalanche risks.
- Increased icy travel east of the Cascades. Persistent cold air may keep snow and ice on highways longer, creating hazardous driving conditions in the Columbia Plateau and Blue Mountains.
Past winters with similar setups show a wide range of impacts. Some La Niña years brought extended cold spells in the Willamette Valley, while others pushed major snow events into Portland and surrounding communities. Even when snowfall totals remain moderate, colder-than-average conditions extend road hazards and strain heating systems.
Travel will be a significant concern. I-5 through the Willamette Valley may see icy stretches, while I-84 through the Columbia River Gorge is prone to closures during snow and freezing rain events. Mountain passes such as Santiam Pass (U.S. 20) and Siskiyou Summit (I-5) often face extended delays during heavy snow periods.
The official winter forecast will be released October 16, but state officials urge Oregonians to prepare now. Residents are advised to winterize vehicles, service furnaces, and keep emergency kits on hand. Farmers and ranchers should prepare for the possibility of higher feed and energy costs if cold snaps linger.
