Arizona Weather Facts and Trivia

Learn More about Phoenix Weather

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••• Sunrise and a Hot Air Balloon. © Judy Hedding

When many people think of Arizona they think of cowboys, and sand dunes, and heat, and cacti. It may come as a surprise that Arizona actually has quite a varied topography, which includes low desert (Phoenix, Yuma), mid desert (Tucson, Wickenburg), high desert (Prescott, Payson, Bisbee, Sedona), plateau highlands (Williams, Page, Holbrook), and cold mountainous regions (Flagstaff, Greer). Arizona is home to this country's largest Ponderosa Pine Forest.

The highest elevation point in the State of Arizona is Humphreys Peak, northwest of Flagstaff, at 12,633 feet above sea level. A popular ski area is in that part of the state. The lowest elevation in Arizona is is the Colorado River south of Yuma, along the Arizona-Mexico border, at 70 feet above sea level.

Here are some additional interesting weather facts about Arizona!

  • A forecast of "Partly Cloudy" or "Partly Sunny", is made when between 3/10 and 6/10 of the sky is to be covered with clouds. The difference between these terms is based on the forecast period itself - during the day, either term could be used. However, for the nighttime forecast periods, a forecast of "partly cloudy" would be the only appropriate term, as there is no sunshine at night!
  • Terms such as "slight chance" of rain (10-20%), "chance" of rain (30-50%) or rain "likely" (60-70%) are used when there is uncertainty of receiving measurable precipitation anywhere in the forecast area (such as the Greater Phoenix Area). For instance, if there is only a 30-50 percent chance that rain will fall anywhere in the Phoenix Metro area, then the forecast will call for a "chance" of rain.
  • "Measurable rain" refers to a rainfall total of 0.01 inches or greater. When you hear the terms "isolated" showers or "few" showers (10-20%), "scattered" showers (30-50%), or "numerous" showers(60-70%), in the forecast, this refers to the percent of the forecast area covered by measurable rain. For instance, "scattered showers" means that the forecast area WILL receive rain, and approximately 30-50 percent of the area will experience showers.
  • Most of the severe weather is seen in Arizona, especially in the Phoenix Metro area, is caused by microbursts--not tornadoes. A "microburst" is a small area of rapidly descending air beneath a thunderstorm. When the descending air hits the ground, it quickly spreads out in all directions, causing very strong, straight-line winds. These winds are commonly as strong as 40-60 mph but can exceed 100 mph at times. Microbursts occur over a rather small space-scale, typically the area affected is less than 2.5 miles in diameter.
  • Although Phoenix residents may feel that their city MUST be the hottest place around at times, top honors go to Lake Havasu City, where the mercury climbed to 128° on June 29, 1994. This bests the Phoenix mark of 122°, set on June 26, 1990.
  • Hawley Lake recorded Arizona's coldest temperature of 40° below zero on January 7, 1971. The coldest temperature recorded in Phoenix was 16°, set on January 7, 1913. Phoenix Sky Harbor Airport, where the official temperature for Phoenix is recorded, rarely gets below freezing(32°F).
  • Typically, the heaviest rain falls during the summer thunderstorm season, or monsoon, in our state. The rain can accumulate very quickly, resulting in flooded streets or washes, and can even cause deaths via flash flooding. In Phoenix, the greatest rainfall in a 24 hour period was 4.98 inches on July 1-2, 1911. This total is quite a bit less than the Arizona record of 11.4 inches, which fell on Workman Creek (near Globe) on September 4-5, 1970. On September 8, 2014 an all-time record for Phoenix went into the books. Not only was 3.29 inches of rain the highest ever amount of rainfall for that date, but it was the most rain for any calendar day in Phoenix.

    Now, let's get to the nitty gritty--desert heat. Yes, it gets hot in Arizona's Sonoran Desert. That's where the Greater Phoenix area is located. Here are some triple digit details and trivia, provided courtesy of the Western Region Headquarters of the National Weather Service.

    Triple Digit Facts for Phoenix

    The highest temperatures ever recorded in Phoenix (as of 2017) were:

    122°F on June 26, 1990;

    121°F on July 28, 1995;

    120°F on June 25, 1990;

    119°F on June 29, 2013; June 20, 2017

    118°F on  July 16, 1925;  June 24, 1929; July 11, 1958; July 4, 1989; June 27, 1990; June 28, 1990; July 27, 1995; July 21, 2006; July 2, 2011; June 19, 2017; July 7, 2017

    More Triple Digit Facts for Phoenix

    • The average number of 100°F or higher days in Phoenix from 1896-2010: 92
    • The average number of 110°F or higher days in Phoenix from 1896-2010: 11
    • The fewest number of 100°F or higher days ever recorded in Phoenix: 48 in 1913
    • The fewest number of 110°F or higher days ever recorded in Phoenix: 0 in 1911
    • The greatest number of 100°F or higher days ever recorded in Phoenix: 143 in 1989
    • The greatest number of 110°F or higher days ever recorded in Phoenix: 33 in 2011
    • The greatest number of consecutive days with temperatures of 100°F or higher: 76 in 1993
    • The greatest number of consecutive days with temperatures of 110°F or higher: 18 in 1974

    Phoenix Triple Digit Extremes

    During the years 1895 through 2010...

    • The first occurrence of 100°F or higher: March 26
    • The last occurrence of 100°F or higher: October 23
    • The first occurrence of 110°F or higher: May 10
    • The last occurrence of 110°F or higher: September 19