CHARM to join CoCoRaHS!

What is the CoCoRaHS network?

CoCoRaHS is an acronym for the Community Collaborative Rain, Hail and Snow Network. CoCoRaHS is a unique, non-profit, community-based network of volunteers of all ages and backgrounds who work together to measure and map precipitation. The goals of the program are: The network originated with the Colorado Climate Center at Colorado State University in 1998 thanks in part to the Fort Collins flood a year prior. In the years since, CoCoRaHS has expanded rapidly with over 3,500 observers in eighteen states. CoCoRaHS is used by a wide variety of organizations and individuals. The National Weather Service, other meteorologists, hydrologists, emergency managers, city utilities (water supply, water convervation, storm water), insurance adjusters, USDA, engineers, mosquito control, ranchers and farmers, outdoor and recreation interests, teachers, students, and neighbors in the community are just some examples of those who visit their web site and use their data.

CoCoRaHS website
Download the CoCoRaHS brochure as a PDF

What are the advantages of CHARM joining CoCoRaHS?

(Your) CHARM measurements will become part of a growing national volunteer precipitation network. You will receive CoCoRaHS information and communications and have full access to their database and visualization tools. You will only have to enter your data in one place - the CHARM website - to be part of both networks. CoCoRaHS data is automatically reported to the NWS via the MADIS data stream, which means your data is used by your local weather office. The network also supports the reporting and archiving of asynoptic (irregular and more frequent reporting) precipitation events which the NWS can use for flash flood or hazardous weather warnings.

Why participate in both networks?

We want to preserve the CHARM database and constituents while making our valuable measurements available to the larger community.

How will this affect current CHARM participants?

This should be transparent to current users. You will continue to report CHARM measurements as you currently do. However, the CHARM data entry and corresponding database will be changed to accept additional input to support the CoCoRaHS network.

What additional data can be entered?

CoCoRaHS supports snow and hail reports as well. The CHARM data entry procedures will allow for asynoptic (irregular and more frequent reporting of) observations.

What is the impact on new CHARM participants?

CHARM will continue to support new users in Limestone and Madison Counties, and the northern portion of Morgan and the northwest portion of Marshall County. New CHARM participants in these regions will receive a standard rain gauge consistent with both CHARM and CoCoRaHS standards.


Technical Contact and Page Curator: Paul J. Meyer (
Responsible Official: Dr. Gary J. Jedlovec (

Last Updated: August 16, 2007