Guerneville (CA) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Guerneville, 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.

Guerneville is known for its substantial rainfall, with annual precipitation reaching 1082 mm (43 in). While the overall climate is wet, there are notable seasonal patterns that create interesting contrasts, as demonstrated in our graph below.

Monthly Precipitation Levels

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

The seasons in Guerneville, bring significant changes in precipitation. The wettest month, December, receives heavy rainfall, with an average of 243 mm (9.6 in) of precipitation. This rainfall is distributed across 13 rainy days.

In contrast, the driest month, July, experiences much less rainfall, totaling 0.9 mm (0.04 in) over a single rainy day. These distinct seasonal differences provide diverse experiences throughout the year.

December, the wettest month, has a maximum daytime temperature of 14°C (57°F). The city receives 160 hours of sunshine in this period. During the driest month July you can expect a temperature of 28°C (82°F). For more detailed insights into the city's temperatures, visit our Guerneville Temperature page.

Guerneville's average annual precipitation is 1082 mm (43 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.

Beijing, China, receives 560 mm (22 in) of annual precipitation, concentrated in the summer months.

In Tokyo, Japan, the average annual precipitation is 1528 mm (60 in), with significant summer rains due to typhoon season.

Bangkok, Thailand, experiences a tropical monsoon climate with 1668 mm (66 in) of annual rainfall, with the heaviest precipitation occurring during September and October.

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.

The proximity of a location to a large body of water can significantly affect its rainfall patterns:

• Ocean Influence: Coastal regions typically receive more rainfall due to the presence of moisture-laden winds from the ocean. These regions tend to have more humid climates and experience more frequent precipitation, especially in winter.
• Continental Climates: Areas further from the sea, such as inland or continental regions, experience less frequent rainfall and more extreme seasonal variations in precipitation.

• "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 Guerneville (CA)'s weather, including sunshine hours, humidity levels, and temperature data, visit our Guerneville (CA) Climate page.