National Weather Service United States Department of Commerce

Join CoCoRaHS Weather Observation Network in Ohio!


The State Climatologist of Ohio and the National Weather Service are looking for volunteer weather observers across the state to collect precipitation data for CoCoRaHS, the Community Collaborative Rain, Hail and Snow Network.


Ohio weather buffs of all ages and backgrounds can join a rapidly growing network of volunteer weather observers across the country. By joining and participating, you will play an active role in meteorological reporting and research using inexpensive equipment (a rain gage) in your backyard.


CoCoRaHS was launched in Colorado in 1998 as a local project by Colorado State Climatologist Nolan Doesken, following a devastating flash flood in Fort Collins. Lacking a dense network, intense rainfall can fall between rain gages. This increases the detection time of a developing flash flood. Since the Fort Collins project, several new states have come on board every year. The program now boasts over 12,000 volunteer observers nationwide with most states participating.


CoCoRaHS partners in Ohio include, the Ohio State Climatologist (Dr. Jeffrey Rogers), scientists from Kent State University, the Ohio Department of Natural Resources, the Central Ohio Raingage Network (organized by Bob Davis of EMH&T Engineers in Columbus), and the 5 National Weather Service offices serving Ohio.


The CoCoRaHS network in Ohio will be divided into 6 regions. Your regional coordinator will be your point of contact should you have a question. All correspondence, data collection and training will be done through the CoCoRaHS web site -


CoCoRaHS observers across the U.S. access the CoCoRaHS web site at to submit daily precipitation data. Tables and maps of the precipitation in each state are then available for all to view online.


The only equipment needed is a 4" cylindrical rain gauge available from the network. In order for reports to be consistent, the use of a 4" rain gage is mandatory. A gage can be purchased for $23 (plus shipping) through the web site. Many commercial weather supply companies also sell the 4" rain gages. A yardstick should be used to measure snow depth.


"CoCoRaHS measurements can provide a detailed look at Ohio rainfall patterns that can help in flood forecasting, disaster management, and drought assessment," said Jeffrey Rogers, the State Climatologist for Ohio at The Ohio State University. Rogers serves as state co-coordinator, along with Brian Astifan of the National Weather Service in Cleveland.


Astifan comments how the launch of CoCoRahs can bring a greater recognition of Ohio's variable precipitation: "Precipitation can vary widely across Ohio. Summer storms can drop 4" of rain in one area, with locations just a few miles away remaining dry. During the fall, if a dying tropical system passes through Ohio, the difference between 3" of rain and no rain can be just 20 miles. Even snow amounts can be quite different just across a single county. The addition of even just a couple of CoCoRaHS observers within a county can help to create more complete precipitation maps during any season."


Click here to visit the CoCoRaHS web site for more information. Click here to sign up to be a CoCoRaHS observer. Note that Pennsylvania is a CoCoRaHS state. Pennsylvania residents interested can also click here to register.


Click here to view the CoCoRaHS page for Ohio.


"CoCoRaHS - Because Every Drop Counts!"