The Pacific Northwest is expected to see a split temperature pattern as the region heads into 2026, with inland areas of Washington and Oregon trending warmer than normal, while coastal and eastern sections remain closer to seasonal averages.
Forecast guidance for the Dec. 27–Jan. 2 period shows a broad ridge of high pressure building over the interior West, allowing milder air to push northward into the inland Northwest. This setup favors above-normal temperatures west of the Cascades but away from the immediate coast, with cities like Portland emerging as potential warm spots heading into the New Year.
In Portland, where average highs in late December typically sit in the mid-40s, daytime temperatures could climb into the mid-50s and possibly near 60 degrees on some days. That would place parts of the Willamette Valley 10 to 15 degrees above normal, an unusual departure for the heart of winter and enough to challenge daily warmth records if cloud cover breaks.
By contrast, western Washington’s coastal communities and eastern Washington and eastern Oregon are expected to remain near normal, with cooler air lingering closer to the Pacific and across higher terrain east of the Cascades. Seattle may still trend mild at times but is less likely to see the same degree of warmth expected farther inland.
Looking ahead to Jan. 3–16, 2026, longer-range outlooks suggest the Pacific Northwest maintains this pattern, with continued above-normal temperatures inland and near-normal readings closer to the coast and east of the mountains. That could delay sustained winter cold in valleys while preserving more typical winter conditions elsewhere.
While this warmth may ease travel and reduce short-term winter weather impacts inland, it raises concerns for mountain snowpack and water supply, especially if the mild pattern limits snowfall at lower elevations.
The takeaway: as 2026 begins, the Pacific Northwest will not warm evenly, with inland areas feeling springlike at times while coastal and eastern zones stay much closer to winter norms.
