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

This page shows the average amount of rainfall per month in Castro Valley (CA). The numbers are calculated over a 30-year period to provide a reliable average. Now, let’s explore all the details to give you a full picture.

On average, Castro Valley receives a reasonable amount of rainfall, with an annual precipitation of 512 mm.

Monthly Precipitation Levels

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

Significant seasonal changes in precipitation occur throughout the year. During the wet season, December receives substantial rainfall, averaging 111 mm of precipitation, recorded across 13 rainy days.

In contrast, the drier season, August brings less rainfall, with 0.1 mm over 0 rainy days.

December, the city’s wettest month, has a maximum daytime temperature of 14°C and receives 160 hours of sunshine. During the driest month August you can expect a temperature of 24°C. For more detailed insights into the city’s temperatures, visit our Castro Valley 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

Castro Valley’s average annual precipitation is 512 mm. Let’s compare this to some popular worldwide tourist destinations:

In Toronto, Canada, annual precipitation averages [964 mm], with snowy winters and rainy summers.

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

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

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.

Global Warming and Precipitation

Climate change is affecting precipitation patterns worldwide, including Castro Valley (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.

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