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

This page shows the average amount of rainfall per month in Union City (CA). The numbers are calculated over a 30-year period to provide a reliable average. Now, let’s break down all the details for a clearer picture.

Union City tends toward drier weather patterns, receiving approximately 354 mm of rain per year.

Monthly Precipitation Levels

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

Union City can be quite wet during December, receiving approximately 81 mm of precipitation over 11 rainy days.

In contrast July, experiences much drier conditions, with 0 mm of rainfall, spread across 0 rainy days.

December, the city’s wettest month, has a maximum daytime temperature of 15°C and receives 160 hours of sunshine. During the driest month July you can expect a temperature of 25°C. For more detailed insights into the city’s temperatures, visit our Union City 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

Union City’s average annual precipitation is 354 mm. Let’s compare this to some popular worldwide tourist destinations:

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

Osaka, Japan, experiences 1507 mm of rainfall annually, spread across the year with wetter summers.

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

Mumbai, India, experiences a tropical monsoon climate with 1860 mm of annual rainfall, with the majority of precipitation happening during the monsoon season from June to September.

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 Union City (CA)’s weather, including sunshine hours, humidity levels, and temperature data, visit our Union City (CA) Climate page.