Colorado State University National Precipitation Monitoring Network Expands to All 50 States on Dec. 1

Note to Reporters: Photos are available with the news release at

Colorado State University State Climatologist Nolan Doesken really just wanted more accurate statistics about Fort Collins rainfall when he created a volunteer precipitation-reporting network in 1998.

Now, the program he created – the Community Collaborative Rain, Hail and Snow Network or CoCoRaHS – will add its 50th state on Dec. 1 when Minnesota formally joins. CoCoRaHS already counts 14,600 volunteers across the country.

“We are pleased that this simple backyard monitoring program has become so popular,” said Doesken, a senior research associate in the Colorado Climate Center in Colorado State’s internationally known atmospheric science department. “These volunteers are providing scientists around the country with excellent precipitation and hail monitoring statistics for tracking weather patterns and water supplies.”

The CoCoRaHS program makes use of volunteers of all ages from children on up to grandparents to document the size, intensity, duration and patterns of precipitation by taking simple measurements in their own backyards. Volunteers only need a cylindrical rain gauge, some training and an interest in weather to participate in the program. The specific rain gauges that CoCoRaHS volunteers use are available from several distributors on the network’s website,, for $25 plus shipping. The site also offers online training.

Data from CoCoRaHS volunteers are now being routinely viewed and used by many professions and organizations including the National Weather Service, meteorologists, hydrologists, emergency managers, city utilities, insurance adjusters, agribusinesses, engineers, science teachers and many more. Data are used for many applications such as water resource planning, severe storm warnings, teaching earth science, predicting crop yields and for assessing hail damage.

Doesken founded the CoCoRaHS program in response to the Spring Creek Flood that devastated Fort Collins on July 28, 1997. For this effort, the National Oceanic and Atmospheric Administration honored him as one of 10 "Environmental Heroes" in 2007. In December 2006, NOAA’s Office of Education awarded CoCoRaHS an Environmental Literacy grant to make its first formal push to expand nationally.

The first five states to join the program – after Colorado – were Wyoming, Kansas, New Mexico, Texas and Maryland. Texas currently has the most volunteers – 1,333 – followed by Colorado with 1,237.

Doesken and the Colorado Climate Center also recently launched the Colorado Climate Trends website – – which was created to allow access to historic climate data simply, easily and graphically. Users may view recent temperature or precipitation conditions and compare them with the recorded historic data from the past century by month, season or year.

For more information or to volunteer for the CoCoRaHS program, go to