The questions that everyone should ask is why would anyone live in Portland, Oregon during the summer, when Seattle and Puget Sound is so close?
Let's review the temperature data, and those in Portland will be excused for skipping the details.
Here is a plot of the temperatures at Sea Tac (red) and Portland (green) airports. Portland is warmer virtually every day, and sometimes by a considerable amount. Portland reaches the 90s F quite frequently
How about the average maximum temperature over the past month? Mid to upper 70s in Seattle, mid to upper 80s in Portland.
Extreme temperatures? Here is a plot of daily highs--yellow lines-- at Portland and Seattle. In Portland, many days have daily records above 100F in mid-summer, several as high as 105-107.
In contrast, Seattle almost never gets to 100F (one day).
OK, it is clear. Portland is a hellishly warm place during the summer. But why? The key is they have poor access to the cool water and thus natural air conditioning of the Pacific. As shown by the terrain map, Portland is in a topographic "bowl", with moderate terrain on all sides. Hard for cool air from the Pacific to get to the city. The Columbia and Willamette rivers are too narrow to do much good.
In contrast, Seattle has direct access to Puget Sound, the Strait is close, and there is a sea level path to the ocean.
Portland Purgatory versus Seattle Cool. Portland also has weird donuts. (see below, so hot down there they put bacon on the donuts)
The only thing that makes Portland livable is a ready supply of chilled microbrews. Without them, Portland would be abandoned during the summer.