Every March, Chicago transforms into a sea of green—but nothing captures the city’s St. Patrick’s Day spirit quite like the tradition of dyeing the Chicago River green. This iconic celebration dates back to 1962, when city officials first poured dye into the river to detect illegal sewage leaks. The vibrant green color was such a hit that it quickly became a beloved annual tradition.

Led by the Chicago Journeymen Plumbers Local 130, this unique event kicks off St. Patrick’s Day festivities in true Chicago style. Using an environmentally safe orange powder (yes orange!), the river magically turns a shade of green that lasts for hours.

The tradition has become a symbol of Chicago’s rich Irish heritage and festive spirit, drawing crowds from around the world. Alongside the famous St. Patrick’s Day Parade, the green river is a must-see spectacle that reflects the city’s pride, community and love for celebration.

As the river glows green, Chicagoans and visitors gather to honor tradition, share in the joy and celebrate what makes this city unique.