Rialto (CA) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Rialto, California, United States of America. This average is based on long-term data collected between 1990 and 2020. Now, let's break down all the details for a clearer picture.

With annual rainfall averaging 291 mm (11 in), Rialto maintains relatively low precipitation levels throughout the seasons. However, it does have a distinct dry season during certain months, creating distinct patterns as demonstrated in our detailed graph 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 86 mm (3.4 in) of precipitation, recorded across 7 rainy days.

In contrast, the driest month, June brings less rainfall, with 0.1 mm (0 in) over 0 rainy days.

December, the wettest month, has a maximum daytime temperature of 18°C (64°F). The city receives 205 hours of sunshine in this period. During the driest month June you can expect a temperature of 31°C (88°F). For more detailed insights into the city's temperatures, visit our Rialto Temperature page.

Rialto's average annual precipitation is 291 mm (11 in). Let's compare this to some popular worldwide tourist destinations:

Seville, Spain, experiences 541 mm (21 in) of rainfall annually, with wet winters and dry summers typical of southern Spain.

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.

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.

• "Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
• The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm (15 inches) wide and 20 cm (7.9 inches) thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
• The greatest snowfall recorded was on Mt. Rainier, Washington State, USA, over 31.5 meters (103 feet) fell during the winter of 1972.

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