Diamond Bar (CA) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Diamond Bar, California, United States of America. Long-term data from 1990 to 2020 was used to calculate these averages. Let's explore the details to provide you with a complete overview.

Diamond Bar's climate is marked by below-average rainfall, accumulating 312 mm (12 in) of precipitation yearly. The distribution includes a distinct dry season during certain months as shown in the precipitation charts below.

Monthly Precipitation Levels

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

The seasons in Diamond Bar, bring significant changes in precipitation. The wettest month, December, receives moderate rainfall, with an average of 84 mm (3.3 in) of precipitation. This rainfall is distributed across 9 rainy days.

December, the wettest month, has a maximum daytime temperature of 19°C (66°F). The city receives 205 hours of sunshine in this period. During the driest month June you can expect a temperature of 30°C (86°F). For more detailed insights into the city's temperatures, visit our Diamond Bar Temperature page.

Diamond Bar's average annual precipitation is 312 mm (12 in). Let's compare this to some popular worldwide tourist destinations:

Athens, Greece, receives an average annual precipitation of 400 mm (16 in), making it one of the drier Mediterranean climates with rainfall mostly in winter.

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.

Kuala Lumpur, Malaysia, receives 2529 mm (100 in) of annual rainfall, characteristic of its equatorial tropical rainforest climate, with consistent rainfall throughout the year and peak months during March and November.

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.

Climate change is affecting precipitation patterns worldwide, including Diamond Bar (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.

• Mawsynram in India is noted as being the wettest place on earth, with over 11 meters (36 feet) of rain falling every year.
• In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm (0.004 inches) 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 Diamond Bar (CA)'s weather, including sunshine hours, humidity levels, and temperature data, visit our Diamond Bar (CA) Climate page.