By Mike Baker, Seattle Times
Looking back at the past 70 years of temperature records in the Seattle area, this decade is beginning to stand out in stark terms.
Seattle finished 2018 with an average high temperature of 62.3 degrees, making it the fifth-hottest year on record in data going back to 1948 at the Seattle-Tacoma International Airport. The only warmer years were 2015 (63.4 degrees), 2014 (62.6 degrees), 2016 (62.5 degrees) and 1992 (62.5 degrees).
So why are so many years from this decade crowding the top of the records books?
Washington State Climatologist Nick Bond said there are two things going on. First, Bond said, there’s no question that the weather data from recent decades shows a baseline warming trend that’s reflective of global climate change that scientists largely attribute to human activities that emit heat-trapping gasses.
The data from the National Climatic Data Center shows the average high temperature in the area was about 58 degrees in the 1950s. It has climbed steadily. And, this decade, the average high is so far surpassing 61 degrees. (Note: We compiled this year’s weather from a combination of records from the National Climactic Data Center, which collects the historical data, and some preliminary local records from the National Weather Service because the national data center’s site is now shuttered because of the federal government’s shutdown.)
Bond said that along with the overall global warming, the last few years in the Seattle area have also been particularly hot. He said climate trends can sometimes develop multiyear warming or cooling periods.
“We’re in a relatively warm period, and so when that is on top of this overall warming trend, it means a disproportionate number of record years are recently,” Bond said.