When was Hurricane Katrina formed and when did it dissipate?

Hurricane Katrina was officially formed on August 23, 2005, in the Bahamas as a tropical depression. It rapidly intensified into a hurricane on August 25 before making landfall in Florida. Katrina then crossed the Gulf of Mexico and made another landfall on August 29 in Louisiana as a Category 3 hurricane. It finally dissipated on August 31, 2005, over the eastern United States.