CoCoRaHS Gauge with Rainbow CoCoRaHS LogoThe Community Collaborative Rain, Hail and Snow (CoCoRaHS) Network is a volunteer, manual precipitation observation network born out of a need for high density precipitation data following a significant flood in Colorado. From its inception, CoCoRaHS has followed a two-pronged approach of educating the
public in climate literacy topics and collecting high quality, high-density precipitation data for use by educational, governmental, and private organizations. Over the last 17 years the CoCoRaHS Network has grown to support all of the United States, Canada, Puerto Rico, and the US Virgin Islands. In that time over 34,000 people have taken precipitation measurements, and their efforts have led to an archive of over 30 million observations. Besides the value to the field of meteorology, CoCoRaHS data are utilized in fields such as snow hydrology, geology, extreme precipitation event analysis, civil engineering, and radar algorithm evaluation.

cocorahs_make_it_rain_gameCoCoRaHS has developed an extensive set of climate literacy educational materials with the help of teachers and 4-H groups. Five years ago the Community Collaborative Schools (CoCoSchools) project was created to further the development and utilization of these materials for use both in and outside of schools. Since then CoCoRaHS staff has given presentations on climate literacy topics at over 130 events including school presentations, water festivals, and teacher workshops reaching over 7,700 people made up of students, teachers, and parents.

Teachers’ Testimonials Regarding CoCoRaHS

CoCoRaHS Observers“[CoCoRaHS is] a way to meet the standards in an authentic way and in a way that connects with real-world science.”

“When we do the, like, snow, the amount of moisture that’s in the snow, that just fascinates the kids.”

“I think it’s great for the kids, they’re highly invested. And I know our school and our principal likes that we do it because it addresses so many math and science standards. Um, but I think it’s a really nice, important first step for even younger learners, like we have K- 3, to just start thinking about weather and thinking about climate and also just seeing how scientists record and observe things.”

“Immediately I saw the benefits [of CoCoRaHS] in so many different ways. It just seemed like a really relevant way to address those standards…as a teacher, I just want young people to have that experience with science and realize that it’s all around us and we can all be scientists and we can all observe and collect data and it has a higher purpose. Today when [CoCoRaHS staff] talked about that NASA satellite that’s all my kids talked about all afternoon, ‘our data is going somewhere, they’re doing something with it.’ They were so excited to think that somewhere out there, what we record everyday matters.”

Climate Literacy Resources for Libraries

We would like to work with libraries to expand and adapt our educational materials for library settings. If your library might be interested in assisting us, please contact us at Some examples include incorporating hands on activities with storytime, using 3-D printers to print out hailstones to examine how the process of hail stone formation causes their irregular shapes, and incorporating use of the CoCoRaHS data API into coding programs.

cocorahs_prism_climate_portalBeing able to summarize, analyze and distill information from large data sets is a crucial skill in the 21st century. What better way to teach kids to do this, than to engage them with data that is relevant to them. When it rains we all get wet, and most people of any age have weather related stories that have made a significant impression on them.

The primary question for observers is: “How much precipitation fell in your backyard?” The types of questions CoCoRaHS data users seek to answer using the resulting data are:

  • How can radar algorithms be improved?
  • What will the stream flow be, based on precipitation rates in a watershed?
  • What level of drainage is needed to prevent urban flooding in an area?
  • What was the water content of the snowfall?
  • Should the NWS issue a severe weather warning in an area?
  • What should the irrigation schedule of farmland be, given the current water balance?
  • How accurate are satellite precipitation estimates?
  • How to best direct mosquito control efforts?

CoCoRaHS Water Balance GraphThe core question of the project is relatively simple and easy to explain, however, the resulting data informs more complex questions from data users across a diverse set of fields.

CoCoRaHS Daily Precipitation Map

Tens of thousands of people who have an interest in the weather and a desire to contribute to their community have found CoCoRaHS a fun and informative way to combine their interests. Due to the highly variable nature of precipitation, the more people participating in the project, the more valuable the data are to the people and organizations that rely on it. We are always looking for more observers, especially in rural communities. If your library or patrons are interested in becoming a CoCoRaHS observer, they can submit an application. If your library is interested in working with CoCoRaHS to bring more climate literacy opportunities to your library, please contact us at