The New Orleans metropolitan area is home to one of the largest Vietnamese diaspora communities in the USA. Its biggest festival is Tết Nguyên Đán, also known as Vietnamese New Year, or (because we're in Louisiana) Tet Fest. A weekend-long party goes off at Mary Queen of Vietnam Church, featuring firecrackers and some amazing Southeast Asian cuisine.
The date of Tet is determined by the Lunar Calendar; if measuring by Western dates, the holiday generally falls in late January or early February. Check www.vietnamonline.com/tet for dates.