Data from CSU-led project shows on-the-ground reports from Hurricane Ian

CoCoRaHS reports

A screenshot of reports to CoCoRaHS the day Hurricane Ian made landfall in Florida.

Data collected by a team of citizen scientists as part of a Colorado State University-led project will help the National Weather Service and meteorologists across the country report on the continued impact of Hurricane Ian. 

The Community Collaborative Rain, Hail and Snow Network – known as CoCoRaHS – began in the aftermath of the 1997 Spring Creek Flood in Fort Collins. It has since grown into a network of 25,000 people across all ages and backgrounds who use rain gauges to provide the NWS with precipitation reports about the conditions in their own backyards. 

“It’s so valuable for the National Weather Service to be able to get reports about what’s happening on the ground because radar and satellite can really only do so much,” said Noah Newman, the education and outreach coordinator for CoCoRaHS. 

CoCoRaHS emphasizes safety above all else. In the aftermath of Hurricane Ian, it received fewer daily reports than usual due to a combination of evacuations and power outages, but the information it did receive was staggering, with precipitation totals in some areas of more than 14 inches in 24 hours.

Sept. 28 vs. Sept. 29 hurricane ian

These numbers are public on the CoCoRaHS and National Weather Service’s websites and have been used in countless television news reports about the storm. 

The interactive map below shows the weather gauge data from Florida as Hurricane Ian made landfall.

Citizen scientists are able to add comments in addition to their precipitation reports, and those have sometimes told stories far beyond the numbers involving their rain gauge. 

“We’ve seen cases of people’s homes being destroyed by fire or tornado or floods,” Newman said. “These comments are public and sometimes go out on Twitter, where we often get an enormous response from the community looking at ways to help.” 

In addition to telling stories of a storm, these real-time reports from the ground can help the National Weather Service issue flash flood warnings after periods of heavy rainfall. Conversely, reports of zero precipitation can help scientists monitor droughts. 

Since its inception, CoCoRaHS has spread to all 50 U.S. states and other locations including Puerto Rico, the Bahamas, Virgin Islands and, most recently, Guam. CoCoRaHS also operates in all provinces in Canada. Newman said the team is always looking for more volunteers. For more information about setting up a weather gauge, visit

“These citizen scientists are doing something very easy but meaningful in making reports to the scientific community,” Newman said. “I think sometimes in these days, it’s easy to feel powerless. This is something tangible that anyone can do to help their community.”