At 3:30 p.m. on Wednesday, December 10, 2025, residents of Sumas, Washington, a community nestled within the Nooksack River floodplain on the state’s northwestern border, received an urgent warning of rising floodwaters. The city’s flood alarm blared with an unsettling wail that carried as far north as Abbotsford, British Columbia, prompting most residents to heed the alert. They quickly gathered their children, pets, and essential belongings, seeking refuge in flood shelters, hotels, or the homes of nearby friends. The following morning, however, the sole routes into and out of Sumas were submerged, leaving the town and its surrounding areas inundated by several feet of frigid, silt-laden river water. This deluge caused extensive damage to hundreds of homes and businesses, coating nearly every surface with a thin layer of mud. Dozens of residents who had not evacuated were airlifted from their rooftops by a U.S. Coast Guard helicopter. By December 12, as the waters began to recede, the high-water mark was starkly visible, marked by debris caught on chain-link fences and muddy streaks adorning nearly every home and vehicle in the affected zones.

The region was battered by two consecutive atmospheric rivers in early December, with some areas experiencing up to 14 inches of rain within a 72-hour period at the storms’ peak intensity. Low-lying agricultural lands bore the brunt of the impact, while the foothills of the Cascade Range and urban centers like Seattle, Everett, and Bellingham experienced less severe effects. The arduous process of recovery has now begun. On December 12, in the town of Nooksack, located just downriver from Sumas, thick work gloves, high rubber boots, and waterproof jackets became the uniform for volunteers assisting homeowners with the sodden task of cleanup. Teams worked to haul waterlogged carpets and building materials to the street for collection, while others ventured into still-flooded crawlspaces, removing soaked insulation and muddied vapor barriers. Additional volunteers, affiliated with the Whatcom Long Term Recovery Group—an organization established after the similarly devastating floods in north Whatcom County in 2021—were stationed at the Nooksack Valley Church. There, they provided assistance in both English and Spanish, helping residents navigate insurance claims and state aid, and offering crucial emotional support as people returned to their devastated community and grappled with the daunting questions of what comes next. As of December 19, nearly 800 families in Whatcom County had formally requested assistance from the recovery group.

Atmospheric rivers, defined as narrow bands of concentrated water vapor originating over the warm waters of the Pacific Ocean, are a regular feature along the West Coast, delivering significant precipitation. However, this particular series of storms proved unusually extensive, dumping rain as far south as central Oregon. In response to the escalating crisis, over 100,000 Washington residents were issued evacuation orders as coastal rivers draining the Cascade Range reached their peak flows on December 11 and 12. In Skagit County, approximately 60 miles north of Seattle, the communities of Concrete and Hamilton were particularly hard-hit. Bridget Moran, a fisheries biologist working in Skagit County who was aiding residents with home cleanup, noted that in some Hamilton homes, the high-water mark exceeded six feet. Further downstream, the Skagit River, flowing at a record-breaking 37.7 feet, was prevented from inundating downtown Mount Vernon only by the presence of a protective floodwall.

Not all communities were as fortunate. In the nearby city of Burlington, 55 homes and sections of the downtown core were flooded on December 12, necessitating the evacuation of nearly 10,000 residents. Further south in King County, floodwaters breached an already weakened levee along the Lower Green River near the town of Pacific in the early morning of December 16. This event triggered the evacuation of 2,100 residents from the affected area, ultimately impacting approximately 220 homes and around 800 individuals. In Snohomish County, south of Skagit County, a 33-year-old man lost his life after attempting to drive on a closed road, becoming the first and, to date, only confirmed fatality attributed to the flooding.

Communities situated at higher altitudes in the East Cascades, such as Naches, Leavenworth, and Methow, typically experience colder and drier conditions compared to areas west of the mountain range. However, due to the unusual pattern of precipitation falling predominantly as rain, even in the highest reaches of the Cascades, these areas also experienced catastrophic flooding, widespread power outages, and significant mudslides. In Stehekin, a community situated near the burn scar of the 2024 Pioneer Fire, residents and businesses suffered substantial damage from landslides and post-fire debris flows in the recently burned areas. The scorched soil and vegetation in these zones are inherently more prone to destabilization. Further south along the Cascade crest, Stevens Pass sustained such severe damage that its closure is expected to last for months, while multiple landslides across eastbound Interstate 90, the primary transportation artery through the Cascades, caused significant disruptions. Washington experienced a third, albeit slightly colder, atmospheric river during the week of December 15. This precipitation fell on watersheds already saturated from the previous week’s rains, leading to further flooding, though of a less severe magnitude. However, the accompanying high winds proved more destructive than the water itself, leaving approximately 380,000 people across the state without power.

The USDA Northwest Climate Hub points to a confluence of factors, including increasingly hazardous atmospheric rivers and the broader impacts of climate change, as drivers of these extreme weather events. A warmer atmosphere possesses a greater capacity to hold moisture, while a warming Pacific Ocean serves as an enhanced source of that moisture. This dynamic leads to an increase in both the duration and intensity of atmospheric river events. Guillaume Mauger, Washington state climatologist, explained that when these elements combine, "we’d expect the storms to be more intense." According to Mauger, the exceptional danger posed by this series of atmospheric rivers stemmed not only from their individual strength but also from their rapid succession. Mauger was careful to emphasize that researchers are still gathering definitive data to fully understand the precise influence of climate change on this specific storm sequence. However, he noted that the unseasonably warm temperatures and the significant shift from snowfall to rainfall were strong indicators of climate change’s role. "Atmospheric rivers are warm in general," he stated, "but if this event had happened in 1950, the snowline wouldn’t have been quite so high. That’s the big effect: that it’s just less snow and more rain."

Communities throughout Washington are now transitioning into the recovery phase, with residents diligently working to salvage belongings and remove water-damaged materials from their homes while simultaneously seeking financial assistance. Washington Governor Bob Ferguson has allocated $3.5 million in emergency funding to aid flood victims and has proposed a supplemental budget including $55 million designated for home repair and recovery efforts. President Donald Trump has approved Governor Ferguson’s request for federal disaster assistance, enabling FEMA (the Federal Emergency Management Agency) to provide support to communities and local governments, although this does not directly unlock federal funding for individual victims.

Several factors are likely to complicate the recovery process in many of the affected areas. A report from the Urban Institute highlights a high proportion of renters, the prevalence of manufactured homes, and a widespread lack of flood insurance as significant challenges. In Whatcom, Skagit, and Snohomish counties, only about a quarter of the homes situated within the 100-year floodplain carry National Flood Insurance Program coverage, a federally administered policy designed for individuals in low-lying areas who might otherwise struggle to obtain insurance. Shortly after the floodwaters receded on December 12, I joined another volunteer in Nooksack to help a family remove ornaments and lights from their Christmas tree, its lower branches now coated in mud, the floor around it thick with silt. Elsewhere in the neighborhood, other volunteers quietly worked, carrying out sofas and children’s toys still dripping with river water. Later, standing in a driveway, I observed volunteers diligently removing sodden items from every home on the block—a scene that would be replicated in thousands of residences across the state in the weeks and months ahead. The sheer scale of the devastation was profoundly sobering, yet there was little time for contemplation; the task at hand was immense, involving the removal of trim, the tearing out of flooring, the completion of countless forms, the rebuilding of lives, and, ultimately, the renewal of communities.