The year is forecast to end on a dry note, following 2015 records for heat and days of heavy rain, and a December that is the second-wettest ever recorded at Seattle-Tacoma International Airport.
Rain-soaked Seattle-area residents could wrap up the year with something they haven’t seen all month: dry days.
After a showery Monday and a 20 percent chance of rain Tuesday, the forecast calls for a sunny Wednesday followed by foggy-but-dry days through the New Year’s weekend.
The reprieve from December rains ushers out a record year at Seattle-Tacoma International Airport, which had its warmest year, its greatest number of superhot days and its highest number of days of heavy rain.
A hot 2015
Seattle recorded a record number of hot days this year.
National Weather Service
Feeling a bit waterlogged? It could be because at least a trace of rain has fallen every day this month.
Even for December, that’s soggy. Last December had 13 dry days, and December 2013 had 16.
With three days to go, this has already become the second-wettest December on record at Sea-Tac, site of the city’s official weather readings since 1945.
Through midday Monday, the airport had recorded 11.19 inches of December rain — more than twice the normal amount for all of December, 5.35 inches.
If the current forecast holds, this month is likely to stay in that No. 2 spot, below the 11.85 inches that fell in December 1979, said Brent Bower, a National Weather Service hydrologist.
Despite a dry middle to the year, Sea-Tac is on pace to finish 2015 at nearly 45 inches of rain, well above the normal amount of 36.85, but less than last year’s 48.34.
A weather-service recap of the year notes that 14 days this year had an inch or more of rain, swamping the previous record of nine such days in 1996 and 2000.
A strong El Niño, with warm waters near the equator in the Eastern Pacific, helped send “atmospheric rivers” toward the Pacific Northwest, according to the weather service.
Among the warm-weather milestones, Sea-Tac is closing out the year with an average temperature of 55.66, passing the record of 54.99 degrees set just last year.
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“There is a slow warming of the climate, but it’s mostly that this has been an unusual weather year,” said state climatologist Nick Bond.
Bond said there has been no single explanation for the warm year but notes that a warm-water mass in the Northern Pacific helped establish a warm-weather pattern even before 2015 started.
While this year’s extreme weather events may not have a direct connection to global climate change, Bond said, they may offer a preview of weather that will be more common as the level of greenhouse gases rises.
Although hot days were the hallmark of summer, data in the recap show warmer-than-usual weather occurred through the year. For example, two days that hit 60 this month (Dec. 3 and 8), tied or set records for those dates.
The weather service also reports that 19 days this year set or tied high-temperature records at Sea-Tac, but no day had a record low temperature.
And about those warm days. Sea-Tac in 2015 recorded its most :
• 90-plus-degree days, with 12, compared to nine in 1958
• 85-plus-degree days, with 26, compared to 22 in 2014, and
• 80-plus-degree days, with 51, compared to 47 in 1958.