Q&AZ: AZ had the highest and lowest temperature in the U.S. How is this possible?

By Andrea Barrios
Published: Wednesday, June 14, 2023 - 5:18pm
Updated: Thursday, June 15, 2023 - 8:39am

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Flagstaff snow
Michel Marizco/KJZZ
Arizona's well-known for its extreme heat but because of the much higher elevations in the northern portions of the state, it can also feature some of the coldest temperatures in the country — sometimes all in the same day.

Through KJZZ's Q&AZ project, a listener noticed that AZ had both the highest and lowest temperature on the same day in all of the contiguous U.S. They asked if this was a one-day fluke or a regular occurrence.

Arizona is famous for its hot weather. But recently, on the same day we registered the highest temperature in the lower 48 states … we also recorded the LOWEST.

Although this high-low phenomenon is extremely rare elsewhere in the U.S., it’s fairly common in Arizona. That’s because of our desert climate and dramatic changes in elevation.

When cities like Phoenix and Yuma are experiencing intense heat, northern Arizona — where elevation stretches beyond 12,000 feet — can feature some of the nation’s coldest temperatures.

Matei Georgescu is the director of the Urban Climate Research Center at ASU. He says, "You have very very extreme elevation differences, which are going to lead to very extreme temperature differences. You don't have this across many other states in the United States."

Arizona’s most recent high-low day occurred on May 29, when the thermometers hit 101 in Phoenix, while dipping to 26 degrees in Coconino County.