Chicago River goes green for St. Patrick’s Day

CHICAGO — Thousands flooded the streets of downtown on Saturday morning to watch the Chicago River turn emerald green in celebration of St. Patrick’s Day 2025.

The annual tradition has been carried out by Journeymen Plumbers Local Union 130 since 1962.

The idea came when a plumber used an orange dye to detect pollution in the river and noticed it turned his overalls green. They then used it to dye the river — and the tradition was born, according to Secret Chicago.

The dyeing got underway at 10 a.m. and thousands lined the streets to catch a glimpse of the iconic event.

40 pounds of the dye, which is eco-friendly, is spread by various boats as they make their way down the river, but the rich green color only lasts for a little while.

The specific recipe for the dye is a closely guarded secret.

Shortly after the dyeing, at 12:30 p.m., the Chicago’s St. Patrick’s Day Parade steps off at Columbus Drive and Balbo. The celebration is one of the largest St. Patrick’s Day parades in the country.