Casper (WY) Rainfall & Precipitation: Monthly Averages and Year-Round Insights

This page shows the average amount of rainfall per month in Casper (WY). 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.

Casper has a relatively dry climate with low precipitation, averaging 360 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 74 mm of precipitation, recorded across 13 rainy days.

In contrast, the drier season, November brings less snow/rainfall, with 11 mm over 5 snowy/rainy days.

May, the city’s wettest month, has a maximum daytime temperature of 18°C. During the driest month November you can expect a temperature of 9°C. For more detailed insights into the city’s temperatures, visit our Casper 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

Casper’s average annual precipitation is 360 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.

Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm of annual rainfall, mostly in the summer.

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.

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