Seattle set record-high December temperatures in 2023, following global trend – “It is unlikely that this would reverse anytime soon, unless there’s very, very drastic reductions in greenhouse gas emissions”

By Lauren Girgis
4 January 2024

(Seattle Times) – If you like the snow, this unusually warm winter likely isn’t for you.

Snow levels this season have been “marginal, to say the least,” said Rune Harkestad, president of Kittitas County’s Kongsberger Ski Club, based east of Snoqualmie Pass.

December did bring a fair share of precipitation, Harkestad said, “but unfortunately, it all came at once, and most of it was rain.” The ski club’s groomer has had to adapt, getting up in the coldest hours of the night to pack down “whatever snow we get,” he said.

“It was pretty clear early on with the mild weather and unusually warm December, that this was going to be a challenge, and it has been,” Harkestad said.

Western Washington broke record-high temperatures in December, as Earth’s rapidly warming winters affect snowfall and winter sports, and as a strong, global, naturally occurring El Niño pushes tropical air into the region. During El Niño, Washington’s winters tend to be warmer than normal and snowpack is more likely to be below normal.

In Seattle, the National Weather Service recorded a mean daily temperature of 45.5 degrees last month, beating the previous record of 45.3 set in 2014. The average December low was 40.4 degrees, and the average high was 50.6 degrees.

Normally, the average low is 37.2 degrees and the average high is 47 degrees. 

“If I were to say tomorrow would be 3 degrees warmer than today, it’s like, ‘big whoop,’” said Karin Bumbaco, the deputy state climatologist at the University of Washington. “But if you look at an average over an entire month, and you have an anomaly that’s 3 to 7 degrees Fahrenheit above normal, that’s pretty substantial.” 

The record-setting difference was even greater in Quillayute, where the mean daily temperature was 48 degrees, 3.5 degrees higher than the previous record set in 2014. […]

Globally, the past nine years have been the hottest nine years on record, and it doesn’t appear the trend will change in 2024.

Average winter temperatures increased in 97 percent of the cities Climate Central studied since 1970. Over that period, the average winter warming across those locations was 3.8 degrees. 

“It is unlikely that that would reverse anytime soon, unless there’s very, very drastic reductions in greenhouse gas emissions,” Bumbaco said. [more]

Seattle sets record-high December temperatures, following global trend