Measuring Rain for Science!


Whether it’s for your garden, or your rain barrel, it’s always good to know how much rain you actually received.  Rainfall is extremely variable; as you’ve probably witnessed, it could be raining across the street but not on you.  You may also know that the amount reported on the news comes from Denver International Airport and will not be the same amount that fell on your garden.  It turns out – scientists want to know how much YOU received too.

CoCoRaHS, the Community Collaborative Rain, Hail and Snow network is a grass-roots volunteer organization where volunteers set up simple – yet accurate rain gauges – and report the data online where it becomes immediately available to view on maps.  The National Weather Service uses the data every day for many uses including ground verification, river and flood forecasts, and even drought.  Because the data is used by scientists and researchers, the main requirement is to use a manual 4-inch rain gauge.  Automated gauges are unfortunately not allowed.  Measurements are typically taken first thing in the morning, but data can be entered at any time, including through the use of a free smartphone App.  Volunteers are not required to report every day, but are encouraged to do so, including reporting zero when no rain fell at all.  Having a complete data set at the end of the year makes it even more valuable to meteorologists, scientists and researchers.

Participating is easy and can be a fun activity for the entire family.  Free tools for volunteers include access to weather and climate experts, tools for viewing and analyzing precipitation data, resources for Master Gardeners and more.  The maps provide one of the best benefits – seeing your data alongside everyone else’s reports show how your report fits into the bigger picture – and gives you bragging rights when you got more than your neighbor.

Join today, and feel free to write to with any questions.