San Diego (CA) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in San Diego, California, United States of America. The figures are based on a 30-year period (1990–2020) to provide a reliable average. Now, let's break down all the details for a clearer picture.

San Diego experiences desert-like conditions in terms of precipitation with almost no rainfall, generally receiving 226 mm (8.9 in) annually.

Monthly Precipitation Levels

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

San Diego can be quite wet during December, receiving approximately 59 mm (2.3 in) of precipitation over 7 rainy days.

In contrast June, experiences much drier conditions, with 0.4 mm (0.02 in) of rainfall, spread across a single rainy day.

December, the wettest month, has a maximum daytime temperature of 19°C (66°F). The city receives 231 hours of sunshine in this period. During the driest month June you can expect a temperature of 22°C (72°F). For more detailed insights into the city's temperatures, visit our San Diego Temperature page.

San Diego's average annual precipitation is 226 mm (8.9 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.

Beijing, China, receives 560 mm (22 in) of annual precipitation, concentrated in the summer months.

Melbourne, Australia, has 690 mm (27 in) of rainfall annually, spread fairly evenly throughout the year.

Ho Chi Minh City, Vietnam, receives 1955 mm (77 in) of annual rainfall, with a pronounced wet season from May to November, typical of its tropical monsoon climate.

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.

• The U.S. has a significant number of thunderstorms every year, with over 14.6 million taking place across the world annually.
• Approximately 70% of lightning bolts strike land rather than oceans.
• A storm named John was the longest-lasting Pacific tropical storm, continuing for 31 days. As it crossed the dateline twice, it changed status from a hurricane to a typhoon and back to a hurricane.

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