Phoenix (AZ) Rainfall & Precipitation: Monthly Averages and Year-Round Insights

This page shows both the average monthly rainfall and the number of rainy days in Phoenix, Arizona, United States of America. These averages rely on historical data collected over 30 years, from 1990 to 2020. Let’s explore the details to provide you with a complete overview.

Phoenix has a dry climate with very low precipitation, averaging 174 mm of rainfall annually.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm)

Phoenix can be quite wet during August, receiving approximately 32 mm of precipitation over 6 rainy days.

In contrast June, experiences much drier conditions, with 1.3 mm of rainfall, spread across 0 rainy days.

August, the wettest month, has a maximum daytime temperature of 40°C. The city receives 360 hours of sunshine in this period. During the driest month June you can expect a temperature of 40°C. For more detailed insights into the city’s temperatures, visit our Phoenix Temperature page.

Annual Precipitation in the United States of America

The map below shows the annual precipitation across the United States of America. You can also select the different months in case you are interested in a specific month.

Amsterdam Precipitation Compared World Wide

Phoenix’s average annual precipitation is 174 mm. Let’s compare this to some popular worldwide tourist destinations:

The city of Rome, Italy, has an average annual precipitation of 832 mm, spread fairly evenly throughout the year.

Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm of annual rainfall, mostly in the summer.

In Tokyo, Japan, the average annual precipitation is 1528 mm, with significant summer rains due to typhoon season.

Bangkok, Thailand, experiences a tropical monsoon climate with 1668 mm of annual rainfall, with the heaviest precipitation occurring during September and October.

How is Precipitation Measured?

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

How Does Precipitation Affect Local Climate?

Precipitation has a very strong role in determining the local climate and ecosystem:

• Rainy Seasons: Many parts of the world have well-defined wet seasons where precipitation is distinctly higher. These are normally accompanied by lush vegetation and temperature patterns.
• Dry Seasons: In areas where the climate is either desert or Mediterranean, the amount of precipitation is drastically reduced, leading to a shortage of water and arid conditions.

For more detailed information about Phoenix (AZ)’s weather, including sunshine hours, humidity levels, and temperature data, visit our Phoenix (AZ) Climate page.