What time will Chicago River be dyed green? A 2026 guide

It's almost that time of year when the streets of Chicago fill with green – from shamrock headbands to leprechaun costumes.

But the residents won't be the only thing turning green for St. Patrick's Day. Chicago will continue its decades-long tradition of dyeing the river green, attracting thousands upon thousands of spectators.

Here's how to prep for the big day.

How long has Chicago been dyeing the river green?

The long-standing tradition started back in 1962, when the Plumbers Local Union decided to try pouring 100 pounds of green dye into the Chicago River for St. Patrick's Day.

This means the custom has been going on for almost 65 years!

Is the green dye used in the Chicago River safe?

The Plumber's Union originally colored the river with an oil-based green dye used to help clean the river's waterfront areas, leaving the water green for an entire week.

The city later switched to a more environmentally friendly powdered, vegetable-based dye, however, according to The Smithsonian. The formula of the dye is kept a secret.

When will Chicago dye the river green?

The river dyeing is typically held the Saturday before St. Patrick's Day.

This year it will land on Saturday, March 14.

What time is Chicago River dyeing?

The river dyeing starts at 10 a.m., though those hoping to snag a good viewing spot will want to get downtown early.

How long does the Chicago River stay green?

The brilliant green color will only last for a few hours, though some Chicago residents have reported seeing traces of green days later.

Best spots to view Chicago River dyeing

Generally, any spot along the river will grant you a view of the vibrant green, though the streets fill up quickly.

Outlets over the years have reported that the best viewing spots are between State and Columbus on Upper Wacker and across the bridges. The Lower Riverwalk is typically closed except for select ticketed events.

Spectators can also view the river dyeing from many of the nearby restaurants and bars, as well as on one of the river cruises.