By the middle of the century, the Southwest region is expected to experience 5 to 30 more days per year with a maximum temperature exceeding 95 degrees F.

The largest simulated increases occur in Arizona and New Mexico, with as many as 25-30 more days above 95 degrees F each year. These hot days are already common in these parts of the region. The smallest increases in hot days occur in high-elevation areas, because projected temperature increases are still not enough to increase the chance of such warm days.

Southern parts of the region could have up to 45 more days each year with maximum temperatures of 90°F (32°C) or higher, by mid century, when compared to the period 1976-2005.