April is Severe Weather Awareness Month for the National Weather Service (NWS). As part of this effort, the Twin Cities office of the NWS, located in Chanhassen, is seeking additional participants for the CoCoRaHS (Community Collaborative Rain, Hail and Snow Network) program. CoCoRaHS observers measure precipitation—rain, hail and snow—that falls at their location (typically their home) and share their observations daily via an online app.
What is CoCoRaHS?
CoCoRaHS is a grassroots, volunteer effort coordinated through Colorado State University to provide precipitation reports from as many locations as possible. While the NWS operates recording stations across the country, it cannot cover every location. Precipitation can vary significantly even within short distances—amounts may differ from one block to the next. The more observations collected, the better the understanding of weather conditions impacting a given area.
On the morning of April 18, eleven reports were submitted for Carver County, ranging from 0.01 inches in the far west of the county to 0.23 inches southwest of Carver. Nationwide on April 18, there were 9,732 observations across the U.S. and Canada, with Minnesota contributing 652.
Current records indicate that Carver County has 114 registered observers, with 58 active and 24 submitted reports at some point in 2026. Nine participants have shared more than 1,000 observations each. The most observations come from near Watertown with 5,825 reports over a span of almost 16 years.
How does it work?
A standard 4-inch-diameter rain gauge is needed to report precipitation for CoCoRaHS These are available from various online retailers. Check the CoCoRaHS website for sources and costs. Additionally, internet access is required to submit reports via a mobile app or website.
Each morning at a set time, observers measure precipitation from the previous 24 hours and report it to the CoCoRaHS system. In winter, snowfall is measured by depth (using a ruler) on the ground or by the liquid equivalent after melting. Short online training and videos are available to help new participants get started. Reporting typically takes fewer than two minutes per day and multi-day reporting options are available for times when observers are away.
Additional precipitation and snowfall reports are especially needed across greater Minnesota to provide CoCoRaHS and the NWS with timely, detailed data that supports improved weather prediction models.
View CoCoRaHS reports via an interactive map at: https://maps.cocorahs.org/
For additional information on the network or to sign up as an observer visit:
