CoCoRaHS cocorahs rain drop image
Community Collaborative Rain, Hail, and Snow Network
cocorahs banner
Massachusetts residents can let us know how much rain, hail or snow you measured in your backyard or schoolyard by joining the Community Collaborative Rain, Hail, and Snow Network - CoCoRaHS. This new program will help meteorologists, researchers, the media, and others see and study the variability of precipitation across the Bay State. The accumulated precipitation data will be available to anyone using the web. If you'd like to contribute valuable precipitation information unique to your location, then this program is for you!
In the near future, CoCoRaHS will expand into other New England states. Vermont will join the network in April.
The CoCoRaHS program began in 1998 after devastating floods in the Denver CO area missed all the official rain gauges. In the years since, the CoCoRaHS network has grown to include over 12,000 observers in 40 states.

Volunteer Observers are now needed to help grow this network across Massachusetts. Volunteer Observers are the backbone of the CoCoRaHS program. Observers record precipitation information using the recommended 4" rain gauge and enter their observations onto the CoCoRaHS webpage. Training slides and information are available at the CoCoRaHS web site. Other Volunteer Observer duties, along with answers to frequently asked questions, can be found searching through the tabs on the CoCoRaHS main web page.

Please visit the CoCoRaHS web site at to learn more about the program and use the “Join CoCoRaHS” link to sign up as an Observer! If you have any questions, the State Coordinator for Massachusetts is Joe Dellicarpini and he can be reached directly by sending an email to
Thanks for your interest in CoCoRaHS - Because Every Drop Counts!