Washington State’s winter weather and storms vary depending on where you are in the state. Its coastal region to the west features marine environments, forests, mountains, and a wet climate. Meanwhile, to the east, you’ll find a drier climate and a geography that’s dominated by plateaus. Then, there’s the Cascade Mountains that run across the length of the Evergreen State and basically separates it into two regions.

In Western Washington is where the majority of the state’s residents live, with cities like Seattle, Vancouver, and Olympia located just west of the mountains. In fact, the region is surrounded by mountains on all sides: the Cascades to the east, the Olympic range to the west, Mt. Baker to the north and Mt. Rainier to the south. In winter, temperatures drop to the 20s and 30s (-6° to -1° C) at night. Clouds often hang in the sky, thanks to the Pacific Ocean, with January and February being the wettest.  

In Eastern Washington, only the Cascade Range has an impact on the weather. In particular, the Cascades hog most of the rain, and in winter, snowfall in the mountains can reach up to 200 inches (508 cm) in a year. Wintertime temperature ranges from the upper 30s (3°C) to just above 0° F (-17° C).

Thanks to its diverse geography, Washington State experiences a variety of winter storms. Though these storms are a regular part of the state’s climate, their frequency and severity is greatly affected by the geographic characteristics of an area, e.g., if it’s in the lowlands or in the mountains. Here are few of the winter storm types that affect Washington state. 

Atmospheric Rivers: The Pacific’s Firehose

Atmospheric rivers dominate Washington’s winter storm conversation, and for good reason. These long, narrow bands of concentrated moisture stretch across the Pacific like massive conveyor belts, carrying tropical water vapor northward. When they slam into Washington’s mountains, the results can be spectacular—and destructive.

“By a global standard, they’re really rivers in the sky,” Marty Ralph, director of the Center for Western Weather and Water Extremes at Scripps Institution of Oceanography at UC San Diego, told San Francisco Chronicle.

A recent example of this phenomenon occurred in December 2025 (atmospheric river storms are common in November and December). A major atmospheric river storm, which was ranked a 4 out 5 on the atmospheric river scale from the Center for Western Weather and Water Extremes at UC San Diego, dumped 20 inches of rain on the Cascade mountain range.

“Many mountain locations in the Olympics and Cascades received 15 inches or more of precipitation (almost all rain) in the 72-hour period” from Dec. 8 to Dec. 11, Clinton Alden, University of Washington Mountain Hydrology Research Group graduate student, told Snoqualmie Valley Record. Massive floods swept through communities across the state as a result. 

Beware of Blizzards

Essentially, blizzards are dangerous snow storms created from the combination of blowing snow and wind which result in very low visibilities. To be officially called a blizzard by the National Weather Service (NWS), the storm must meet the following criteria: 

• Contain large amounts of snow or blowing snow, 

• With winds in excess of 35 mph, 
• Visibilities of less than 1/4 mile, and 
• Last for an extended period of time (at least 3 hours).

Often, heavy snowfall and severe cold accompany a blizzard, but that’s not always mandatory. For instance, strong winds can pick up already fallen snow and create a ground blizzard.

Blizzards occur occasionally in the state. For instance, back in 1950, certain places in Washington State were paralyzed and several casualties recorded because of a blizzard. The January 1950 Blizzard followed the coldest winter on record for Seattle, which received over 20 inches of snow in one day.

“Downtown Seattle picked up an average of 10 inches of snow, but farther south Sea-Tac Airport recorded 21.4 inches, the second-greatest 24-hour snowfall ever officially recorded in the city (it was one-tenth of an inch shy of tying the record),” historian Phil Dougherty shares at HistoryLink.org. “Snow reached clear to Washington’s southwest coast with heavy snow reported in Longview.” 

Ice Storms: The Silent Danger

While less common than snow or rain, ice storms or silver thaws present unique hazards across Washington state. Freezing rain develops when warm air overrides cold surface air and creates a temperature profile that melts falling snow then refreezes it on contact with surfaces. 

This means that roads, concrete, and other exposed surfaces will be slippery and dangerous to traverse on. Ice storms can also cause widespread power outages and damage trees. 

Table 1. Types of Impacts and Damage from Different Accretion of Ice

Ice Accretion	Types of Damage
Nuisance-Type Event Less than 0.25 inches	Minor power outages Light accumulations of ice on trees Car windshields coated in ice Slippery roads leading to very dangerous driving conditions
Disruptive Ice Storm Between 0.25 and 0.50 inches	Numerous power outages Damage to trees and power lines Very slick driving conditions
Crippling Ice Storm More than 0.50 inches	Severe damage to trees, e.g., numerous downed trees  Severe damage to power lines leading to widespread power outages that might last for days

Source: Fox 13 Seattle

A narrow area westward from the Columbia River Gorge to the vicinity of Vancouver sees the most significant ice storm activity in the state.

Preparing for Washington’s Winter Reality

Understanding Washington’s winter storm types helps residents prepare more effectively. Emergency management professionals recommend different preparation strategies for different regions and storm types. Coastal residents need flood preparation supplies, mountain residents need extended power outage supplies, and eastern Washington residents need extreme cold preparation.

The key insight from meteorological professionals and emergency managers? No single preparation strategy works statewide. But understanding your local storm patterns—whether that’s atmospheric rivers, blizzards, or ice storms—dramatically improves your ability to weather whatever winter throws at you. Because in Washington State, winter weather isn’t just about temperature and precipitation. It’s about understanding the complex dance between ocean, mountains, and atmosphere that creates some of the most varied winter weather in the nation.