By the middle of the century, the Northwest region is expected to experience 3 to 18 more days per year with a maximum temperature exceeding 95 degrees F, and the hottest day of the year is projected to warm by 6.25°F.

The largest simulated increases occur in southern Idaho, with as many as 18 more days above 95 degrees F each year. The smallest increases in hot days occur in high-elevation areas of the Cascades and Rocky Mountains, because projected temperature increases are still not enough to increase the chance of such warm days.