2015 was hottest year on record in Washington

Last year was by far Washington’s warmest ever recorded, according to meteorologist Nic Loyd of Washington State University’s AgWeatherNet in Prosser.

“At 3.9 degrees above-normal average temperatures, 2015 surpassed the hot Dust Bowl’s record year of 1934 by 0.9 degrees,” he said. Last year’s average temperature in Washington was 50 degrees, compared to its yearly average of 46.1.

At the Hanford nuclear reservation, where records are kept back to World War II, 2015 also was the warmest year on record, with temperatures averaging 3.6 degrees above normal.

A report by the National Oceanic and Atmospheric Administration analyzing data going back to 1895 said Oregon, Montana and Florida experienced a record year of warmth as well. Idaho, California and Alaska had their second warmest year.

Much of the boost in the Northwest came during an unprecedented heat wave in June, when temperatures in many locations ran about 25 degrees above normal.

June 2015 was the warmest June on record in the Tri-Cities, with temperatures for the month averaging 8.6 degrees above normal, according to the National Weather Service. At Hanford the heat set 11 daily temperature records and tied two others that month.

February, March, July and October also saw warmer-than-usual temperatures across the state, said Loyd, who monitors weather data for AgWeatherNet, a network of 171 weather stations statewide.

“The consistency of abnormal warmth throughout the year was remarkable,” he said.

A super-charged El Niño weather pattern and a persistent “monster ridge” of high pressure parked over the Pacific Northwest were big contributors, he said.

The high-altitude ridge blocked cooler and wetter weather from entering the region. At the same time, El Niño, a natural, periodic warming of the equatorial Pacific Ocean that releases heat into the atmosphere, brought more heat and dryness.

“Although El Niño typically brings rainfall to central and southern California, it can result in warmer weather and less precipitation across the Pacific Northwest,” Loyd said.

However, the new year is off to a good start for precipitation in Eastern Washington. A recent parade of storms over the Cascade Mountain Range has dumped enough snow to significantly curb drought conditions that plagued the region in 2015.

“In one month, the amount of snow that fell is higher than what we got all of last winter,” Loyd said.

This story was originally published January 12, 2016 at 10:21 AM with the headline "2015 was hottest year on record in Washington."