One of the world's most famous St. Patrick's Day traditions is the annual dyeing of the Chicago River but do you know when it turns green this year?

Before we get to that, here’s a quick background on the history of this memorable Irish themed tradition.

What year was the Chicago River first turned green for St. Patricks Day?

The first official dying of the Chicago River for St. Patricks Day took place in 1962, almost 60 years ago.

Whose idea was it to dye the Chicago River green for St. Patricks Day?

The origins for dying the river date back before 1962.

Irish American Mayor of Chicago, Richard J. Daley, whose parents were from County Waterford, was attempting to develop the city’s riverfront area.

However, the river was heavily polluted with sewage and an eyesore so Daley authorized the pouring of a special green dye into the river to pinpoint the exact places where waste was being discarded into the waterway.

Read more: When are St Patrick’s Day 2019 parades taking place in Dublin, New York, Boston and Chicago?

Mayor Daley. Image: Getty

Mayor Daley. Image: Getty

In 1961, Stephen Bailey, the city’s St. Patrick’s Day Parade chairman, and a member of the Chicago Journeymen Plumbers Local Union 130 UA, witnessed a colleague’s green-soaked coveralls following a day of pouring dye into the river.

Bailey, a close friend of Mayor Daley, then came up with the idea to turn the whole river green.

When will the Chicago River be dyed green for St Patrick's Day in 2019?

The Chicago River will be turned green on Saturday, March 16, this year.

St. Patrick’s Day is officially March 17, but Chicago, like many other US cities will celebrate the occasion the day before.

Read more: Mesmerizing sequence of photos of the dyeing of the Chicago River for Paddy’s Day (VIDEOS)

Workers spread an orange powder to dye a downtown section of the Chicago River green to begin the city's St. Patrick's Day celebration. Image: Getty

Workers spread an orange powder to dye a downtown section of the Chicago River green to begin the city's St. Patrick's Day celebration. Image: Getty

How long does it take to turn the Chicago River green?

From start to finish it takes about 45 minutes to turn the entire area of the Chicago River green and it stays that way for around five hours.

What time does the dying of the Chicago River start?

The process of turning the water green begins at 9 am and the river only keeps its color for about five hours, so by 2:45 pm, it should be back to normal!

Who turns the Chicago River green and how do they do it?

Representatives of the Journeymen Plumbers Local Union 130 pour orange dye into the Chicago River using two boats, one large and one small.

The larger boat heads out onto the water first, and its crew uses flour sifters to spread the dye into the river. Once the orange dye hits the water it turns green!

The smaller boat follows closely behind in order to help disperse the substance.

Read more: Stop dyeing Chicago river green for Paddy’s Day demand environmentalists

Thousands of spectators watch as the Chicago River is dyed green prior to the annual St. Patrick's Day parade in Chicago, Illinois. Image: Getty

Thousands of spectators watch as the Chicago River is dyed green prior to the annual St. Patrick's Day parade in Chicago, Illinois. Image: Getty

Where is the best place to watch the Chicago River turn green?

The dyeing takes place between Columbus Drive and State Street, so head to the Michigan Avenue bridge or grab a spot along the Riverwalk for the best views of the action.

When is Chicago’s St. Patricks Day parade this year?

This year’s St. Patricks Day parade takes place the same day as the dyeing of the Chicago Rover on March 16, the parade kicks off at noon and lasts for about three hours. It will be broadcast live by ABC 7 Chicago.

St Patrick’s Day 2019: Looking for events in your community this St Patrick’s Day or to share further information on the March 17 celebrations in your area? Join our St Patrick’s Day 2019 group and celebrate St Patrick’s Day 2019 in proper Irish style.

Will you be attending the dyeing of the Chicago River this year? Have you witnessed it before? Let us know in the comments!

Thousands of spectators watch as the Chicago River is dyed green prior to the annual St. Patrick's Day parade in Chicago, Illinois.Getty Images