Snow and Ice

Key Points

  • Seattle's weather is regulated by the Pacific Ocean, which remains relatively even in temperature throughout the year. Occasionally, cold air from the interior of the continent pushes into the Puget Sound region and causes dramatic cold spells, ice, and snow.

  • While Seattle does not receive as much snow on average as many parts of the country, snowfall is not uncommon and can be heavy.

  • Accurate weather records began only about 100 years ago, but based on historical accounts, Seattle's winters seem to have been colder and snowier in the 19th and early 20th centuries.

  • Meteorologists have made great strides in forecasting snow and ice storms. Roughly 80% of snow storms in the Puget Sound lowlands occur when cold air from the interior of the continent pushes through the Frasier Gap near Bellingham and meets a low-pressure system coming off the ocean. If the cold front lingers, snow and ice can be on the ground for weeks.538.

  • Snow and ice impede transportation and because most social and economic activity is dependent on transportation, snow and ice have serious impacts, especially if it remains on roadways for many days.

  • Other significant impacts from snow are:o Public safety impacts resulting from the inability to get emergency vehicles where they need to go.o Utility outages as power demand peaks and pipes freeze. Power losses during extreme cold have resulted in deaths from carbon monoxide poisoning when victims attempted to keep warm by lighting charcoal fires indoors.o Economic losses due to business closures and lost wages by workers unable to get to work or required to stay home with children when schools and childcare facilities close.

  • Seattle does not have dedicated snow plows. Trucks have to outfitted with snow removal equipment when snow threatens. There are not enough of these trucks to plow every street in the city.

  • Due to Seattle's steep topography, some streets are too steep to keep open during snow and ice events.

  • During snow and extreme cold, Public Health - Seattle & King County issues public warnings about the dangers of carbon monoxide poisoning. A regional "Take Winter by Storm" campaign also helps educate on winter preparedness and safety.

  • Occasionally, rapidly melting snow can contribute to saturating the ground and becomes a factor in triggering landslides. The last time this happened was in the winter of 1996/97.

  • Snow load has collapsed roofs, most recently in 1996/97.

To read more about Snow, Ice and Extreme Cold click here