Press release from the National Weather Service office on Woodley Island:

Do you ever wonder how much rainfall you received from a recent thunderstorm? How about snowfall during a winter storm? If so, an important volunteer weather observing program needs your help! The Community Collaborative Rain, Hail, and Snow network, or CoCoRaHS, is looking for new volunteers across northwest California. This grassroots effort is part of a growing national network of home-based and amateur rain spotters with a goal of providing a high density precipitation network that will supplement existing observations.

CoCoRaHS came about as a result of a devastating flash flood that hit Fort Collins, Colorado, in July 1997. A local severe thunderstorm dumped over a foot of rain in several hours while other portions of the city had only modest rainfall. The ensuing flood caught many by surprise and caused $200 million in damages.

A CoCORaHS rain gauge. Famartin, CC BY-SA 4.0, via Wikimedia Commons

CoCoRaHS was born in 1998 with the intent of doing a better job of mapping and reporting intense storms. As more volunteers participated, rain, hail, and snow maps were produced for every storm showing fascinating local patterns that were of great interest to scientists and the public. Recently, drought reporting has also become an important observation within the CoCoRaHS program across the nation. In fact, drought observations from CoCoRaHS are now being included in the National Integrated Drought Information System.

How does one become a CoCoRaHS observer? Go to the CoCoRaHS website above and click on the “Join CoCoRaHS” emblem on the upper right side of the main website. After registering, take the simple online training, order your 4 inch rain gauge and start reporting!

To obtain a rain gauge Volunteers can order through the CoCoRaHS website for about $35 plus shipping. We do have a limited number of rain gauges to give out if you are able to be a regular observer and there is a limited number of observers currently in your area.

Apply with this form.

Observations are available on maps and reports for the public to view within five minutes of submitting them. The process takes only five minutesa day, but the impact to the community is tenfold: By providing high quality, accurate measurements, the observers are able to supplement existing networks and provide useful results to scientists, resource managers, decision makers and other users. If you have any questions, feel free to email Matthew Kidwell at the NWS in Eureka at or call at 707-443-6484 and talk to Matthew Kidwell, Scott Carroll or Ed Swafford.