Chicago River Turns Green for St. Patrick's Day

Annual tradition returns as the river is dyed green for the holiday celebration.

Mar. 13, 2026 at 2:34pm

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The iconic Chicago River dyeing tradition returns this Saturday, March 13, 2026, as the waterway is transformed into a brilliant shade of green to celebrate St. Patrick's Day. The process takes about an hour, with members of the Chicago Plumbers Union using a special dye mixture that changes color once it hits the water. While the initial green hue only lasts for a few hours, the river will retain a green tint for several days after the initial dyeing.

Why it matters

The annual dyeing of the Chicago River is a beloved tradition that has taken place for decades, drawing large crowds downtown to witness the spectacle. It serves as the kickoff to a day of St. Patrick's Day festivities across the city, including parades, parties, and other celebrations of Irish culture and heritage.

The details

The dyeing process begins around 10 a.m. on Saturday, with boats from the Chicago Plumbers Union spraying an orange dye mixture into the river. As the dye hits the water, it transforms into a vibrant green color that lasts for several hours before slowly fading. While the initial green hue is the most dramatic, the river will retain a green tint for a few days after the initial dyeing.

  • The river dyeing process takes about 45 minutes to an hour to complete.
  • The live stream of the event will begin at 10 a.m. on Saturday, March 13, 2026.

The players

Chicago Plumbers Union

The union members responsible for dyeing the Chicago River green each year, using a special dye mixture and plumbing equipment to spray the water.

Choose Chicago

The city's tourism organization, which provides information about the annual river dyeing and other St. Patrick's Day festivities in Chicago.

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What they’re saying

“The impeccable brilliant green only lasts for a few hours, with Choose Chicago explaining the water will retain a shade of green after the initial dyeing, but it will slowly fade over time.”

— Choose Chicago (nbcchicago.com)

What’s next

Viewers can tune in to the live stream on NBC Chicago's website, app, and streaming channels starting at 10 a.m. on Saturday to watch the river dyeing process unfold.

The takeaway

The annual dyeing of the Chicago River is a beloved tradition that marks the start of St. Patrick's Day celebrations across the city. While the initial vibrant green hue only lasts for a few hours, the river will retain a green tint for several days, allowing residents and visitors alike to enjoy the festive display.