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CoCoRaHS observers provide a great service to the community by providing information on precipitation across the state. This information is used by scientists, community officials, farmers, emergency managers, and your friends and neighbors to see where daily precipitation has occurred in Illinois. Anyone with an interest in the weather or the environment is welcome to participate.

What Do I Need

The only requirements for participation are an enthusiasm for watching and reporting weather conditions and a desire to learn more about how the weather can affect and impact our lives.You must also use the standard 4-inch rain gauge to measure your precipitation. Even if you already have some other type of rain gauge such as a digital or automatic gauge often included with home weather stations, you will need to use the standard rain gauge. For an explanation on why CoCoRaHS uses the 4 inch gauge, please go here.

How Do I Join

It's easy to sign-up to become an observer - click on "Join CoCoRaHS" and complete the on-line application form. Once you sign up, you will receive a login and password. After you have a rain gauge and begin making observations, you can log in and report them. Your precipitation observations will start showing up daily on our county maps.

How Do I Obtain a Rain Gauge

If you do not currently have a 4-inch rain gauge, you can order your CoCoRaHS rain gauge from for approximately $33 plus shipping. This is a special price for CoCoRaHS observers, and you will not find a lower price anywhere else. You can get a discounted rain gauge by going to at


Training is required! These training sessions are great opportunities to learn from the experts and to meet your fellow CoCoRaHS observers. Attendance at a training session is preferred, but if that is not possible you may take the online training available on the CoCoRaHS web site. There is no charge to attend a training session.

Here are the currently scheduled training sessions. Training sessions will typically last about two hours. Additional sessions will be scheduled in the near future. Please check this web page often for updates!

Illinois CoCoRaHS Training Sessions

Please note the starting time of the session you are interested in attending. Be sure to check back for updates as we add additional training dates this year.

 No training sessions scheduled at this time. Check back again for possible sessions, most of which are conducted in the Spring. Online training is available here and also please review the animated videos on procedures for reporting.