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

This page shows the average amount of rainfall per month in South San Francisco (CA). The numbers are calculated over a 30-year period to provide a reliable average. Let’s explore the details in depth to provide you with a complete overview.

South San Francisco tends toward drier weather patterns, receiving approximately 488 mm of rain per year.

Monthly Precipitation Levels

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

The climate in South San Francisco shows significant variation throughout the year. Expect 114 mm of precipitation during the wettest month December, distributed over 13 rainy days.

In contrast, July offers drier and sunnier days, with around 0.5 mm of rainfall over a single rainy day.

December, the city’s wettest month, has a maximum daytime temperature of 14°C and receives 160 hours of sunshine. During the driest month July you can expect a temperature of 21°C. For more detailed insights into the city’s temperatures, visit our South San Francisco 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

South San Francisco’s average annual precipitation is 488 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.

In Seoul, South Korea, the average annual precipitation is 1237 mm, with most rain falling during the summer monsoon season.

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

Kuala Lumpur, Malaysia, receives 2529 mm of annual rainfall, characteristic of its equatorial tropical rainforest climate, with consistent rainfall throughout the year and peak months during March and November.

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.

Sea vs. Land Precipitation

The proximity of a location to a large body of water can significantly affect its rainfall patterns:

• Ocean Influence: Coastal regions typically receive more rainfall due to the presence of moisture-laden winds from the ocean. These regions tend to have more humid climates and experience more frequent precipitation, especially in winter.
• Continental Climates: Areas further from the sea, such as inland or continental regions, experience less frequent rainfall and more extreme seasonal variations in precipitation.

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