Average Yearly Rainfall in Phoenix, AZ

Storm clouds raining on rock formations in desert landscape
••• Dave and Les Jacobs / Getty Images

Most people understand that Phoenix, Arizona is located in the desert—the Sonoran Desert, to be precise. Deserts are very dry, so you may have wondered—does it rain in Phoenix?

Yearly Rainfall 

You m. In the Phoenix area, the average annual rainfall usually falls between 4 and 8 inches per year. That isn't much compared to other major cities in the U.S. Still, Phoenix gets more rain than Las Vegas, which averages only about 4.5 inches per year. For instance, Los Angeles gets about twice as much rain as Phoenix does and Seattle gets about four times as much rain. 

Phoenix's wettest year since 2000 was 2008 (9.58 inches of rain) and the driest was 2002 (2.82 inches of rain). The annual average rain in Phoenix* from 1971 to 2000 was 8.29 inches; from 2000 to 2015 it was 6.54 inches.

Rainy Season

There are times during the year when it is more likely to rain than at other times. The Sonoran Desert is actually one of the wettest deserts in the world, with two "rainy" seasons from December to March and June to September.

In the Spring, the rains follow California patterns, and you can often predict when wet days will come to Phoenix based on when Los Angeles gets rain.

From mid-June through September Phoenix experiences monsoon thunderstorms. It is not unusual for there to be high winds and rain during that time, often resulting in flooded roads and property damage. There are occasional microbursts. In September 2014 Phoenix received more than 5 inches of rain in just that one month, which was very unusual!

Driving in Phoenix Rain

Because it doesn't rain very often in the Phoenix area, there are two things to remember about driving in wet weather:

  1. Windshield wipers dry out. They are made of rubber, and when we go weeks or months at a time without rain, they may crack and break when you need them most. The rubber parts of the windshield wipers are easy to replace. Local auto parts stores carry a supply, but those stores are jammed and may run out when the rain in Phoenix finally comes. Make sure your wipers are still in good condition and ready to help with visibility during Phoenix rain showers by periodically using the windshield washer. That way, you can tell if they have separated, cracked or are otherwise in need of replacement.
  1. Roads can be extra slick during the rain. During dry periods, a buildup of dirt and oils develops on roads that may become very slick when that rain finally arrives. Leave extra room between your car and the car in front of you, in case you need to make a sudden stop. Make sure you know how to handle your vehicle if you get caught in a skid or hydroplaning situation by reading the vehicle's manual.
  2. Phoenix rarely has consecutive days of light drizzle. When the rain comes, it usually comes down hard and fast! That's when washes and low places quickly fill up with water. If a road is flooded, don't assume that you can just drive your vehicle through it. Each year, many rescues must be performed for stranded motorists who tried to drive through raging washes or standing water that was deeper than they thought. If you happen to be one of those people, you could be charged under the Stupid Motorist Law.