The Pacific Northwest has cooler summer temperatures due to its coastal proximity and the moderating effect of the Pacific Ocean.

The Pacific Northwest experiences cooler summer temperatures primarily because of its coastal proximity and the maritime influence of the Pacific Ocean. The ocean helps moderate the climate by absorbing and releasing heat more slowly than land, which results in milder temperatures. Coastal cities like Seattle and Portland benefit from this effect, experiencing cooler, more comfortable summers compared to inland areas. The cool ocean breeze keeps the region’s temperatures from rising too high, making the Pacific Northwest known for its pleasant, moderate summer weather, especially when compared to hotter inland climates in the U.S.