Aircraft at higher elevations are already operating in thinner air, so temperatures don’t have to climb as high to affect takeoff performance. Airliners need room to build enough speed for takeoff when temperatures soar, and shorter runways leave less distance to do that, Price said. While triple-digit temperatures come with desert living, the kind of hot days that might affect flights are becoming more frequent in both Phoenix and Las Vegas. The following year, the airline canceled dozens of regional flights in Arizona as temperatures in Phoenix climbed toward 120 F (49 C). In July 2018, some airlines bumped passengers at Denver International Airport to later flights as temperatures reached 98 F (37 C), KDVR-TV in Denver reported.