San Gabriel (CA) Rainfall & Precipitation: Monthly Averages and Year-Round Insights

This page shows the average amount of rainfall per month in San Gabriel (CA). The numbers are calculated over a 30-year period to provide a reliable average. Now, let’s break down all the details for a clearer picture.

San Gabriel maintains relatively dry conditions year-round, recording average annual precipitation of 329 mm.

Monthly Precipitation Levels

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

Significant seasonal changes in precipitation occur throughout the year. During the wet season, December receives substantial rainfall, averaging 82 mm of precipitation, recorded across 8 rainy days.

In contrast, the drier season, August brings less rainfall, with 0.4 mm over 0 rainy days.

December, the city’s wettest month, has a maximum daytime temperature of 20°C and receives 220 hours of sunshine. During the driest month August you can expect a temperature of 32°C. For more detailed insights into the city’s temperatures, visit our San Gabriel 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

San Gabriel’s average annual precipitation is 329 mm. Let’s compare this to some popular worldwide tourist destinations:

The climate in San Francisco, USA, is influenced by coastal weather, with 469 mm of rainfall mostly during the winter months.

In Shanghai, China, the annual average precipitation is 1347 mm, with a humid subtropical climate.

In Brisbane, Australia, the annual precipitation is 979 mm, making it wetter than Sydney.

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

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.

Interesting weather facts

• "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 wide and 20 cm 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 fell during the winter of 1972.

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