How about the rest of the northern Arizona high country?

Due to the complex terrain that stretches across central and northern Arizona, large temperature variations are likely over small geographic areas. Two of these examples are the temperature difference between the top and bottom of the Grand Canyon and between the cities of Flagstaff and Sedona.

1. Daytime high temperatures at the South Rim of the Grand Canyon can be as much as 20-23 degrees Fahrenheit cooler, on average, compared to the bottom reaches of the Canyon.
2. Many summer nights can see a large temperature gradient between Flagstaff and Sedona. Flagstaff can have low temperatures in the forties or fifties, while Sedona will be twenty to thirty degrees warmer due to Sedona's proximity next to Oak Creek Canyon and at the base of the Mogollon Rim.

Does northern Arizona ever experience heat waves?

Yes. Although much of northern Arizona is not as hot as the lower deserts in southern and western Arizona, much of northern Arizona is susceptible to heat waves that stretch across the Desert Southwest. The warmest locations during extreme heat waves tend to be the valleys and basins of Yavapai and Gila counties, within the immediate Page, Arizona and Lake Powell region, and within the Grand Canyon. Temperatures in these areas can easily exceed 105-115 degrees Fahrenheit in the late afternoon.

So what is the highest temperature ever recorded in Flagstaff?

So, when did the highest temperature occur in Flagstaff? If you guessed 1974, I'm sorry to say you'd be wrong. It actually occurred the summer previous to that, on July 5, 1973. On that day, clear skies and light westerly winds led to an afternoon high temperature of 97 degrees. This was after an early morning low temperature of 51 degrees. Therefore, the temperature (at least in the last 100 years of record keeping) has never officially reached 100 degrees in Flagstaff. However, at slightly lower elevations, the temperatures have reached 100 degrees in communities surrounding Flagstaff.

What is the highest temperature ever recorded in Arizona?

The warmest temperature ever recorded at an official NWS weather observing site came from Lake Havasu City on June 29th, 1994 when a temperature of 128 degrees Fahrenheit was recorded!