Colorado Volunteers Needed to Measure Rainfall in Their Backyards

CoCoRaHS, the Community Collaborative Rain, Hail and Snow Network, is celebrating its 10th year anniversary with a campaign to find 500 additional volunteers this year.

Started in 1998 as a result of the 1997 Fort Collins flash flood, the network now has more than 10,000 observers across 33 states. State residents of all ages are measuring rainfall in their own yards, which is making a difference in providing accurate precipitation information to area weather scientists.

For more information or to register as a volunteer, go to

"We desperately need help measuring rainfall across Colorado – it’s fun, easy, and only takes a few minutes," said Henry Reges, CoCoRaHS national coordinator at Colorado State University. "Once you get started and see your rainfall amounts on the CoCoRaHS website, you’ll realize how practical and useful the project is. CoCoRaHS data are being used by a wide range of organizations – the National Weather Service, engineers, teachers, research scientists and many more.

"Our observations can make a difference and could even help save lives by giving forecasters advanced warnings of developing flash floods," Reges added. "We’ve even seen mosquito control units use CoCoRaHS to estimate where the pooling of water may contribute to West Nile virus outbreaks. Each volunteer observer is like a pixel on a photo. The more pixels, the sharper the picture of rainfall that has fallen."

"It is amazing to see how much rainfall varies across our communities, which is why this task is so important," said Nolan Doesken, state climatologist at Colorado State University who founded the CoCoRaHS program. "The more observers we have, the better data we’ll have for studying storms, tracking drought, monitoring water supplies and assessing crop conditions."

Anyone with an interest in weather and access to the Internet can sign up. The only equipment needed is a 4-inch diameter, high-capacity rain gauge available from the network for $22 plus shipping.

Training for new volunteers is available online. Volunteers are asked to read rain gauges each morning and upload measurements to the CoCoRAHS website.

"We need as many rain gauges as possible in backyards all around Colorado to help map Colorado rain patterns," Doesken said. "Precipitation here is precious, and the mountains cause even more variability. Knowing more about our rainfall patterns is really helpful."

One local volunteer says that it’s a great motivator to get her retired husband up out of bed each morning. Additionally, CoCoRaHS can be a practical home schooling activity. There have always been Coloradoans who love weather and have been measuring precipitation for years. CoCoRaHS provides a repository for weather lovers to share their observations with others.