Phoenix (AZ) Monthly Rainfall & Precipitation

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 (6.9 in) of rainfall annually.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

Phoenix can be quite wet during August, receiving approximately 32 mm (1.3 in) of precipitation over 6 rainy days.

In contrast June, experiences much drier conditions, with 1.3 mm (0.1 in) of rainfall, spread across 0 rainy days.

August, the wettest month, has a maximum daytime temperature of 40°C (104°F). The city receives 360 hours of sunshine in this period. During the driest month June you can expect a temperature of 40°C (104°F). For more detailed insights into the city's temperatures, visit our Phoenix Temperature page.

Phoenix's average annual precipitation is 174 mm (6.9 in). Let's compare this to some popular worldwide tourist destinations:

The city of Rome, Italy, has an average annual precipitation of 832 mm (33 in), spread fairly evenly throughout the year.

Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm (39 in) of annual rainfall, mostly in the summer.

In Tokyo, Japan, the average annual precipitation is 1528 mm (60 in), with significant summer rains due to typhoon season.

Bangkok, Thailand, experiences a tropical monsoon climate with 1668 mm (66 in) of annual rainfall, with the heaviest precipitation occurring during September and October.

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.

Climate change is affecting precipitation patterns worldwide, including Phoenix (AZ):

• Changing Rainfall Patterns: Global warming causes drastic changes in the patterns of rainfall. Some areas have been experiencing increased frequency and intensity of rainfall, while other areas experience longer dry spells or even droughts.
• Local Impacts: Many regions are experiencing heavier rainfall in the winter months and drier, hotter summers. This affects agriculture, water resources, and ecosystems.

• "Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
• The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm (15 inches) wide and 20 cm (7.9 inches) thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
• The greatest snowfall recorded was on Mt. Rainier, Washington State, USA, over 31.5 meters (103 feet) fell during the winter of 1972.

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