The Official WeatherBug Community
The Community Collaborative Rain, Hail and Snow (CoCoRaHS) network is a grassroots network of volunteers who measure daily precipitation using a manual rain gauge (all volunteers must use the same style 4-inch plastic rain gauge). Measurements are reported at 7:00 AM local time (2 1/2 hour window allows for flexibility) and are immediately available to the public on maps and in list format. The data is used by several entities including NOAA's National Weather Service, NASA, and many more. Data from consistent volunteers with at least 100 daily reports are included in the countless products that utilize the Global Historical Climatology Network (GHCN). Many weather enthusiasts know that measuring precipitation accurately is not always easy, and comparing their automated precipitation data to the manual CoCoRaHS gauge can be a fun experiment - and an eye opening activity. Currently, volunteers must reside in the United States, Puerto Rico, U.S. Virgin Islands or Canada.