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

This page shows the average amount of rainfall per month in San Marcos (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.

With annual rainfall averaging 309 mm, San Marcos maintains relatively low precipitation levels throughout the seasons.

Monthly Precipitation Levels

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

The seasons in San Marcos, bring significant changes in precipitation. The wettest month, December, receives moderate rainfall, with an average of 79 mm of precipitation.

This rainfall is distributed across 8 rainy days. In contrast, the driest month, June, experiences much less rainfall, totaling 0.6 mm over a single rainy day. These distinct seasonal differences provide diverse experiences throughout the year.

December, the city’s wettest month, has a maximum daytime temperature of 19°C and receives 231 hours of sunshine. During the driest month June you can expect a temperature of 27°C. For more detailed insights into the city’s temperatures, visit our San Marcos 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 Marcos’s average annual precipitation is 309 mm. Let’s compare this to some popular worldwide tourist destinations:

In Barcelona, Spain, the average annual precipitation is 620 mm, evenly distributed across the year with no extreme wet or dry seasons.

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.

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.

Interesting weather facts

• Mawsynram in India is noted as being the wettest place on earth, with over 11 meters of rain falling every year.
• In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm per year, with some years recording virtually no rainfall.
• Nearly 1,650 thunderstorm cells are estimated over the planet at any given time.

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