Oregon heat wave
© MOLLY J. SMITH / Statesman JournalBoats on the Willamette River on Saturday, Sept. 2, 2017, near Salem's Riverfront Park. The high for Saturday was forecast for 104 degrees; the National Weather Service issued a heat advisory lasting until Tuesday.
Salem recorded its hottest August temperatures since records started being kept in 1893.

The five warmest Augusts have taken place in the last five years, said David Elson, a meteorologist with the National Weather Service - Portland.

"It's pretty clear that something is going on that we are changing our climate," said Kathie Dello, deputy director of the Oregon Climate Service at Oregon State University. "We're seeing climate change impacts already and we need to think about resiliency toward these 100-degree days."

The hot, dry conditions in the Mid-Willamette Valley are a result of a persistent pattern of the growing drier conditions and lack of rain.

Salem recorded just .15 inch of rain on August 13 - the only day there was precipitation in August.

Average rainfall for Salem in August is .45 inches.

The National Weather Service issued a heat advisory that will remain in effect until 10 p.m. Tuesday. Temperatures are expected to creep into the high 90s on Sunday, hover around 100 degrees on Monday and may reach 103 degrees on Tuesday.

"Normal temperatures would be around 80 degrees around this time of year," Elson said. "We'll be in the ballpark for record temperatures in the next few days."

Oregon is abnormally dry and on the cusp of drought conditions, according to the National Drought Mitigation Center.

The center, which monitors broad-scale conditions, reported Oregon is experiencing abnormally dry conditions.

A drought summary for Oregon, Washington and Idaho stated temperatures have been warmer than normal in the Pacific Northwest as a whole in August.

The arid conditions come months after Oregon's wettest winter since 1999, which brought just under 50 inches of rain in Salem.

The heavy rain saturated the soil and snowfall left Oregon with a heavy snowpack that was expected to prevent severe wildfires.

"As far as the drought goes, I think the (rainfall) helped replenish the soil during the winter and even into the summer months," Elson said. "We had a couple winters where it wasn't anywhere near as well, so we just got started on a good foot."

Despite the record rainfall, however, Dello said Oregon is slowly crawling toward a drought.

Dello said people often correlate drought with rain, but said temperature plays a bigger role in dry conditions. She points to the dry Oregon winter in 2015, when there was no snow, and to 2016, when the snowpack melted at an abnormally fast rate.

"The hot summer is stressing demand a little bit," Dello said. "When the snowpack melts out too soon or we can't capture it, that's when the temperature is really controlling our water situation."

The National Drought Mitigation Center's outlook on the drought conditions a season out from now suggest there will be little to no change in Oregon's current drought levels.

"I would interpret that as we're on the border of no change on the drought or no anticipated worsening of the drought," Elson said.

Dello said the way people talk about climate change has evolved.

"It's happening now and we can start to tie some of these events to climate change," Dello said.

Andy Bryant, a hydrologist with the National Weather Service - Portland, said there has been an obvious trend of increasing temperatures over the past 50 years in the Mid-Willamette Valley.

He said climate model projections show temperatures will gradually increase over time.

"It's more function of pressure patterns, and how much marine air influence we have in the Willamette Valley," Bryant said. "There are long term trends that show summer temperatures."

While Dello said the potential drought is a concern, she said the blazing wildfires are at the forefront of her focus.

"It creeps up slowly and it still surprises us so one of the things we're trying to do is get a better handle on those conditions," Dello said.