Become a Michigan CoCoRaHS Observer!

What is CoCoRaHS?

Who uses the data?

Call for volunteers

Who can participate?

How do I join?

What is the difference between a CoCoRaHS observer and a spotter?

Additional information


What is CoCoRaHS?

On July 1st, 2008, Michigan became the 34th state to participate in a national Community Collaborative Rain, Hail, and Snow Network, or CoCoRaHS. CoCoRaHS is a dense network of volunteers who measure and report precipitation. The network is made up weather enthusiasts of all ages and backgrounds who send in daily observations from their homes, schools, and businesses.

The network originated with the Colorado Climate Center at Colorado State University in 1998, a year after a major flood occurred in Fort Collins.  In the years since, CoCoRaHS has expanded rapidly with over 9,000+ observers in more than thirty states.

The goals of the program are to:

1) provide accurate high-quality precipitation data for our many end users on a timely basis

2) increase the density of precipitation data available throughout the country by encouraging volunteer weather observing

3) encourage citizens to have fun participating in meteorological science and heighten their awareness about weather

4) provide enrichment activities in water and weather resources for teachers, educators and the community 


Who uses the data?

CoCoRaHS data is used by a wide variety of organizations and individuals.  The National Weather Service, other meteorologists, hydrologists, emergency managers, local media, city utilities (water supply, water conservation, storm water), insurance adjusters, USDA, engineers, mosquito control, ranchers and farmers, outdoor & recreation interests, teachers, students, and neighbors in the community are just some examples of those who visit the CoCoRaHS Web site and use the data. Data can be viewed at:


A call for volunteers:

The Michigan State Climate Office at Michigan State University and the National Weather Service are looking for observers to join the Michigan CoCoRaHS Network. Ideally, we would like to have one observer per square mile in urban areas and one observer every 36 square miles in rural areas, so we need many volunteers!


Who can participate?

Anyone with an interest in learning more about the weather! It's fun, requires minimal training, and only takes about 5 minutes or less each day! CoCoRaHS observations can be taken from your home, school, or office.

To be part of the CoCoRaHS network, you will need:

1) an official 4" diameter rain gauge (ordering information)

2) to attend a 90-minute training session

3) an internet or phone connection

4) an interest in the weather!


How do I join?

Joining CoCoRaHS is easy! To start, observers will need to fill out an application and either attend a live 90-minute training session or complete the online training. Live training sessions will soon be scheduled throughout Michigan. Please visit the Michigan CoCoRaHS website for a list of training sessions in your area.


What is the difference between a CoCoRaHS observer and a spotter?

A spotter is a volunteer trained to report severe weather to the National Weather Service. Spotters only report when and if severe weather occurs. A CoCoRaHS observer measures precipitation at the same time each day and submits the data to the CoCoRaHS network. CoCoRaHS observers report precipitation every day, even if it is zero. People with an interest in weather are certainly encouraged to both join the CoCoRaHS network and become a spotter.


Additional information can be found at:

Michigan CoCoRaHS:

National CoCoRaHS: is the U.S. government's official web portal to all federal, state and local government web resources and services.