ADOT Communications Home Page Home Page 

About Safety Weather Gallery Partners Links Contact

Learn More about Arizona Weather

haboob over Arizona 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 in the Grand Canyon, 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 degrees on June 29, 1994. This bests the Phoenix mark of 122 degrees, 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 degrees, set on January 7, 1913. Phoenix Sky Harbor Airport, where the official temperature for Phoenix is recorded, rarely gets below freezing (32 degrees 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.

Credit: "©2002 by Judy Hedding ( Used with permission of About, Inc. which can be found on the Web at All rights reserved."

    Arizona Department of Transportation    
   Disclaimer & Privacy Statement  |   Contact ADOT