Jan. 6, the 12th night on the biblical calendar, marked the beginning of the 153rd annual pre-Lenten celebration. Before it wraps up Feb. 24, almost 100 parades will have rolled in the area and thousands of riders will have thrown tonnes of glitzy gee-gaws to what organizers hope will be huge crowds.
"The celebration is pretty local for a couple of weeks," said Mardi Gras historian Errol Laborde. "But the parades kick in just before the end of the month, and then it's pretty much nonstop."
Mayor Ray Nagin acknowledged the start of the season with the city's annual king cake party, slicing up dozens of pastries covered with purple, green and gold icing, and each holding a tiny, plastic baby. Tradition has it that the person getting the baby in their slice of cake must supply the next king cake.
King cakes, believed to have originated in France around the 12th century, are eaten throughout Carnival season, but on 12th night, or the Feast of the Epiphany, they mark the arrival of the three wise men bearing gifts 12 days after Christmas.
In New Orleans, with its tourism-oriented economy, the rowdy celebration represents both fun and business.
"This is a time of year when everybody can kind of get together and do their own thing and make money at the same time," Nagin said. "So we're looking forward to it."
Unlike last year, when the NBA All-Star game and the Bowl Championship Series title game were added to the city's usual lineup of the Bayou Classic, New Orleans Bowl, and Sugar Bowl, this year Mardi Gras will stand as the solitary big money draw between the Sugar Bowl and Jazz Fest.
A study by a Tulane University economist in 2000 showed a steady growth in Mardi Gras attendance and spending over a decade. Although that dropped after hurricane Katrina in 2005, the event has been rebuilding since then.
Mardi Gras generates more than US$1 billion in spending each year, said Mary Beth Romig of the Greater New Orleans Visitors and Convention Bureau.
Similar but smaller celebrations are held along the French-influenced Gulf Coast.
Despite the financial downturn nationally and a sluggish tourism economy, hotel bookings for Mardi Gras are ahead of last year's pace, said Mavis Early, executive director of the Greater New Orleans Hotel and Lodging Association.
"We are very happy with Mardi Gras bookings to date, and we expect to have the best year yet since Katrina," Early said.
Billed as the "Greatest Free Show on Earth," there is no charge to those attending the parades, but for those riding on the floats, the cost can be high. The riders shoulder the cost of all "throws" - the strings of beads, toys and trinkets showered on crowds along the parade route.
At Randazzo's Camellia City Bakery, one of more than a dozen bakeries that ship king cakes nationally and internationally, orders for king cakes began coming in before Christmas, said saleswoman Cindi Picou, and will continue through "Fat Tuesday."
"We'll send out more than 2,000 cakes in the next few weeks," Picou said Tuesday.
As the season kicked off Jan. 6, the group Phunny Phorty Phellows was scheduled to take its traditional streetcar ride up St. Charles Avenue, signalling the official start of the season.
The Phorty Phellows, an historic Mardi Gras organization, this year was hosting the king and queen of Zulu, the traditional black Carnival organization that is celebrating its 100th anniversary.
"The Phorty Phellows is a low-key event," Laborde said. "It's just one streetcar full of people, but there are people along the route who set up tables and have buffets and champagne to mark the passing. It's a symbol of the opening of the season."