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

This page shows the average amount of rainfall per month in Guerneville (CA). The numbers are calculated over a 30-year period to provide a reliable average. Let’s explore the details in depth to provide you with a complete overview.

Guerneville is known for its substantial rainfall, with annual precipitation reaching 1082 mm.

Monthly Precipitation Levels

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

The climate in Guerneville shows significant variation throughout the year. Expect 243 mm of precipitation during the wettest month December, distributed over 13 rainy days.

In contrast, July offers drier and sunnier days, with around 0.9 mm of rainfall over a single rainy day.

December, the city’s wettest month, has a maximum daytime temperature of 14°C and receives 160 hours of sunshine. During the driest month July you can expect a temperature of 28°C. For more detailed insights into the city’s temperatures, visit our Guerneville 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

Guerneville’s average annual precipitation is 1082 mm. Let’s compare this to some popular worldwide tourist destinations:

In Barcelona, Spain, the average annual precipitation is 644 mm, evenly distributed across the year with no extreme wet or dry seasons.

In Seoul, South Korea, the average annual precipitation is 1237 mm, with most rain falling during the summer monsoon season.

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

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

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.

Interesting weather facts

• "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 wide and 20 cm 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 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.