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

This page shows the average amount of rainfall per month in San Bernardino (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 Bernardino has a relatively dry climate with low precipitation, averaging 276 mm of rainfall annually.

Monthly Precipitation Levels

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

The climate in San Bernardino shows significant variation throughout the year. Expect 86 mm of precipitation during the wettest month December, distributed over 7 rainy days.

In contrast, June offers drier and sunnier days, with around 0.2 mm of rainfall over 0 rainy days.

December, the city’s wettest month, has a maximum daytime temperature of 19°C and receives 205 hours of sunshine. During the driest month June you can expect a temperature of 32°C. For more detailed insights into the city’s temperatures, visit our San Bernardino 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 Bernardino’s average annual precipitation is 276 mm. Let’s compare this to some popular worldwide tourist destinations:

In Lisbon, Portugal, the average annual precipitation is 774 mm, characterized by wet winters and dry summers typical of the Mediterranean climate.

Osaka, Japan, experiences 1507 mm of rainfall annually, spread across the year with wetter summers.

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

Mumbai, India, experiences a tropical monsoon climate with 1860 mm of annual rainfall, with the majority of precipitation happening during the monsoon season from June to September.

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.

Global Warming and Precipitation

Climate change is affecting precipitation patterns worldwide, including San Bernardino (CA):

• 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.

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