Boise (ID) Rainfall & Precipitation: Monthly Averages and Year-Round Insights

This page shows the average amount of rainfall per month in Boise (ID). The numbers are calculated over a 30-year period to provide a reliable average. Let's now guide you through the details for a complete overview.

Boise typically sees modest rain/snowfall throughout the year, with an average annual precipitation of 326 mm.

Monthly Precipitation Levels

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

The climate in Boise shows significant variation throughout the year. Expect 49 mm of precipitation during the wettest month December, distributed over 14 snowy/rainy days.

In contrast, August offers drier and sunnier days, with around 8.3 mm of rainfall over 4 rainy days.

December, the city’s wettest month, has a maximum daytime temperature of 4°C and receives 103 hours of sunshine. During the driest month August you can expect a temperature of 32°C. For more detailed insights into the city’s temperatures, visit our Boise 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

Boise’s average annual precipitation is 326 mm. Let’s compare this to some popular worldwide tourist destinations:

Seville, Spain, experiences 541 mm of rainfall annually, with wet winters and dry summers typical of southern Spain.

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.

Singapore, situated near the equator, gets 2581 mm of rainfall annually, with no distinct dry season and consistent monthly precipitation.

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 Boise (ID)’s weather, including sunshine hours, humidity levels, and temperature data, visit our Boise (ID) Climate page.