Recording Rainfall

Historically, the months of May and October are when we receive the most rainfall in Grayson County.  Do you have a rain gauge at your home?  Many gardeners, homeowners, and farmers are interested in how much rain they get; listening to the weather report can inform you somewhat, but different, even nearby areas may receive differing amounts of precipitation  This post, on a citizen science project - CoCoRaHS -  was originally published on May 19, 2016.

By Sue Abernathy

Are you interested in knowing exactly how much rainfall you receive at home?

Do you wonder if the amount of precipitation varies greatly across Grayson County?

Would you like to have a permanent record of the total rainfall received in a given month, for the entire year and in previous years? If so, the Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) is for you!

CoCoRaHS is a “national grassroots, non-profit, community-based, high-density precipitation network made up of volunteers of all ages and backgrounds who take daily measurements of precipitation right in their own backyards.” The CoCoRaHS network originated at Colorado State University in 1998 with the intent of mapping and reporting intense storms. Since its inception, precipitation maps have been produced for every major storm. These maps show local weather patterns which are of great interest to scientists and the public. Today CoCoRaHS includes thousands of volunteers nationwide who are willing to spend a few minutes each day measuring and reporting precipitation.

CoCoRaHS has several goals:

1) provide accurate high-quality precipitation data on a timely basis

2) increase the density of precipitation data available throughout the country

3) encourage citizens to participate in meteorological science and heighten awareness about weather

4) provide enrichment activities and weather resources for teachers, educators, and the community.

So why participate in CoCoRaHS? Precipitation is essential for life. However, it varies greatly with storm type, season and location. Data sources are few and rain gauges are far apart. Measurements using different style rain gauges are not always accurate. Participation in CoCoRaHS provides quality precipitation data which is viewable immediately in both map and table form. “By providing your daily observation, you help fill in a piece of the weather puzzle that affects many across your area in one way or another.”

CoCoRaHS data is used by the National Weather Service, NOAA (National Oceanic & Atmospheric Association), USDA, and local meteorologists. It provides a historical record of precipitation (and drought) and is used in predicting long-term weather patterns.


How can you become a CoCoRaHS volunteer? Training is provided to teach new observers how to install their rain gauge, properly measure precipitation and submit reports online. It is important that all reports be as accurate and consistent as possible. 

• To join the CoCoRaHS network, submit an application online at www.cocorahs.org. Upon joining, you will receive a CoCoRaHS station ID unique to your specific rain gauge location. 
• To complete the required training, either view the ‘Getting Started’ training slide show online or attend a local training session. 
• Next, purchase a 4-inch diameter high capacity rain gauge, accurate to the nearest hundredth of an inch, which is available from several sources: www.weatheryourway.com, www.ambientweather.com or your county coordinator. 
• Install your rain gauge and begin measuring and recording daily precipitation observations online, including days with no rain. (To participate, you must have daily access to a computer.)

There are currently over 15 active CoCoRaHS participants within Grayson County. With less than an hour of training and the purchase of an approved rain gauge, you can become a CoCoRaHS observer. For more information, contact Sue Abernathy, Grayson County Coordinator via CONTACT for the Friends of Hagerman, and join the CoCoRaHS network!

NOTE: Sue Abernathy is a Grayson County Master Gardener and Texas Master Naturalist, Bluestem Chapter, and as a Friends of Hagerman volunteer, a butterfly garden volunteer and garden docent.