El Cajon (CA) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in El Cajon, California, United States of America. The numbers reflect climate data gathered over a 30-year period, from 1990 to 2020. Let's explore the details to provide you with a complete overview.

El Cajon maintains relatively dry conditions year-round, with an average annual precipitation of 278 mm (11 in). However, it does have a distinct dry season during certain months, creating distinct seasonal patterns visible in our monthly breakdown below.

Monthly Precipitation Levels

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

Significant seasonal changes in precipitation occur throughout the year. During the wettest month, December receives substantial rainfall, averaging 75 mm (3 in) of precipitation, recorded across 9 rainy days.

In contrast, the driest month, June brings less rainfall, with 0.4 mm (0.02 in) over 0 rainy days.

December, the wettest month, has a maximum daytime temperature of 20°C (68°F). The city receives 231 hours of sunshine in this period. During the driest month June you can expect a temperature of 28°C (82°F). For more detailed insights into the city's temperatures, visit our El Cajon Temperature page.

El Cajon's average annual precipitation is 278 mm (11 in). Let's compare this to some popular worldwide tourist destinations:

The climate in San Francisco, USA, is influenced by coastal weather, with 469 mm (18 in) of rainfall mostly during the winter months.

In Shanghai, China, the annual average precipitation is 1347 mm (53 in), with a humid subtropical climate.

Perth, Australia, receives 565 mm (22 in) of rainfall annually, mostly during the winter months.

Ho Chi Minh City, Vietnam, receives 1955 mm (77 in) of annual rainfall, with a pronounced wet season from May to November, typical of its tropical monsoon climate.

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.

Precipitation has a very strong role in determining the local climate and ecosystem:

• 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.

• The U.S. has a significant number of thunderstorms every year, with over 14.6 million taking place across the world annually.
• Approximately 70% of lightning bolts strike land rather than oceans.
• A storm named John was the longest-lasting Pacific tropical storm, continuing for 31 days. As it crossed the dateline twice, it changed status from a hurricane to a typhoon and back to a hurricane.

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