floating yellow buoy can be seen in water through a boat window

Data buoys, also known as weather buoys, are loved by boaters, swimmers, paddlers, fishermen and anyone who uses the water recreationally or for work. Knowing weather and wave conditions before going out on the water makes boating and other activities safer. Many people use our website and follow our Two Yellow Buoys on Twitter to get information on water and air temperature, wind speed and direction, wave height and more about southern Lake Michigan. While the buoys are out on the water, we host real-time data on our website for nearshore conditions off the coasts of Michigan City, Indiana, and Waukegan, Wilmette and Winthrop Harbor, Illinois.

Rich Armstrong of BoatUS Magazine highlighted these “weather watchdogs” and Illinois-Indiana Sea Grant’s Jay Beugly—our buoy handler—in his article “Data Buoys: Sentinels of the Sea,” as part of the December 2019 issue.

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Join the 2026 Great Lakes BioBlitz! 🌎🦋📸Starting Earth Day, educators, students, youth groups, and families are invited to help document biodiversity across the Great Lakes region using iNaturalist. A kick-off webinar is scheduled for April 16th at 2 pm CT.Participate anytime during the four‑week event. Snap photos, make observations, and contribute to real conservation data while getting students outside and engaged with nature. Learn more and get ready to explore: https://sites.google.com/wisc.edu/annual-great-lakes-bioblitz/2026 #TeachingTuesday#GreatLakes
Don’t miss out! Join us for a deep dive into the latest Lake Michigan fisheries science.Topics will include:-Reef restoration impacts on aquatic and fish species-Wild reproduction rates for salmon and trout species from the Great Lakes Mass Marking Program-Fisheries update from the Illinois Department of Natural ResourcesLearn more & register: https://purdue.ca1.qualtrics.com/jfe/form/SV_86eBlPnbjdm7pPg