It's hot on Portland's east side.

New research from Portland State University, first reported by the Portland Tribune, shows that the temperature difference on the east and west side of the Willamette River can vary by as much as 20 degrees—with hotter temperatures on the east side.

Courtesy PSU
Courtesy PSU

Vivek Shandas, urban studies professor at PSU, attributes the heat differential to the way the neighborhoods are designed. The West Hills area is more tree-lined than less-dense developments on the east side, and downtown Portland gets more shade thanks to large buildings.

Still, Shandas told the Tribune he was "particularly surprised by the stark difference between the east and west sides of town."

Some of the hottest areas recorded were in the Eastside Industrial District, the Columbia Corridor and Swan Island.

Shandas and student researchers in PSU's Institute for Sustainable Solutions have been mapping Portland temperatures with a thermocouple unit, which they invented, for the past couple years to track the relationship between the design of developments and heat variance.

Portland, Shandas says, could to better to design developments with a mind for temperature reduction.

Parks, trees, white roofs, shade structures, fewer expanses of asphalt (parking lots), vegetation on walls and increased circulation between buildings are all features that help keep certain areas from becoming "heat islands"—places that absorb heat during the day and release it in the evening after the sun has set.

The city has already been hit with a couple heat waves this summer—with temperatures the past few days nearing 100 degrees Fahrenheit.

At least anecdotally, this east side dweller can confirm—it's hot on the other side of the river.