Seattle weather: After drama, a dry, unseasonably warm end to 2025

If the weather wizards are on their game, Seattle may finish out the year not with a bang, but a whimper — and most of us are probably fine with that.

After weeks of wild, often catastrophic weather, much of Western Washington will be calmer and drier in the final days of 2025 — and is still on track for the warmest December on record.

Thanks to an upper-level high-pressure ridge, dry conditions should persist in and around Seattle though New Year’s Eve before a new system brings light lowland rain and a few inches of mountain snow on New Year’s Day, the National Weather Service in Seattle said Sunday.

“Compared to the last couple of weeks, I would say it’s (going to be) pretty calm,” said Melissa Gonzalez-Fuentes, a weather service meteorologist. “Even with the weather system that’s coming in, we’re not necessarily seeing anything super impactful.”

Later in the week, the National Weather Service expects a new weather system to move into the area, suggesting an “active” weather pattern could persist into the weekend.

As a result, the “threat of minor coastal flooding increases late in the week,” the weather service reported. However, the forecast noted of the new system, “At this time it does not appear to exacerbate coastal flooding.”

In the meantime, lingering atmospheric moisture will likely result in patchy overnight fog, while calm conditions resulting from the upper level ridge could produce stagnation, the weather service said.

With Seattle-area temperatures in the Seattle area forecast to run from the low 30s to around 50, this December could wind up being the warmest on record. 

Through Sunday, the average temperature for December was 46.3 degrees, Gonzalez-Fuentes said. If that holds, we’ll beat the record of 45.5 degrees.

Granted, the current drier conditions come with the possibility of slightly cooler temperatures for the final days of the year — just since Christmas Day, in fact, December’s average high has fallen from 46.8 degrees — so “let’s see how it finishes out,” Gonzalez-Fuentes said.

Record-breaking or not, a few days of drier weather will be a boon to travelers coming home from the holidays, especially those heading over the Cascades, which were hit hard with snow in recent days. 

Snoqualmie Pass was reporting mostly bare and dry conditions on Interstate 90 as of Sunday morning, according to the state Department of Transportation website. 

The drier weather will also be helpful for road crews scrambling to repair sections of highway washed out in recent flooding. 

On Monday, road workers expect to reopen a section of Highway 2 from Coles Corner, in Chelan County, up to Stevens Pass, which has been closed since a massive atmospheric river deluged the Cascades and took out major sections of highway.

Stevens Pass, the one Cascade Mountain ski resort that had not yet opened this year, plans to start welcoming skiers Monday morning.

Granted, they’ll need to take a major detour via I-90 and Highway 97 to get there.  But thanks to this weekend’s heavy snowfall, those who make the trip will find a 50-inch base and 28 inches of new snow since Friday, according to the ski area’s website.