Boulder (CO) Rainfall & Precipitation: Monthly Averages and Year-Round Insights

This page shows the average amount of rainfall per month in Boulder (CO). 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.

Generally, Boulder has a moderate amount of precipitation, averaging 513 mm of rain/snowfall annually.

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, May receives substantial rainfall, averaging 80 mm of precipitation, recorded across 12 rainy days.

In contrast, the drier season, January brings less snowfall, with 16 mm over 5 snowy days.

May, the city’s wettest month, has a maximum daytime temperature of 21°C. During the driest month January you can expect a temperature of 8°C. For more detailed insights into the city’s temperatures, visit our Boulder 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

Boulder’s average annual precipitation is 513 mm. Let’s compare this to some popular worldwide tourist destinations:

Chicago, USA, sees an annual precipitation of 1062 mm, with rain and snow contributing to its humid climate.

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

Melbourne, Australia, has 690 mm of rainfall annually, spread fairly evenly throughout the year.

Ho Chi Minh City, Vietnam, receives 1955 mm of annual rainfall, with a pronounced wet season from May to November, typical of its tropical monsoon climate.

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.

How Does Precipitation Affect Local Climate?

Precipitation has a very strong role in determining the local climate and ecosystem:

• Rainy Seasons: Many parts of the world have well-defined wet seasons where precipitation is distinctly higher. These are normally accompanied by lush vegetation and temperature patterns.
• Dry Seasons: In areas where the climate is either desert or Mediterranean, the amount of precipitation is drastically reduced, leading to a shortage of water and arid conditions.

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