Hurricane Katrina: A Timeline


5 p.m.: The National Hurricane Center in Miami, Florida issues its first advisory about the tropical system that will later become known as Hurricane Katrina. The advisory notes that the season's 12th tropical depression has formed over the Bahamas.

Note: The 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history, repeatedly shattering previous records. A record 28 tropical and sub-tropical storms formed, of which a record fifteen became hurricanes. Of these, seven strengthened into major hurricanes, a record-tying five became Category 4 hurricanes and a record four reached Category 5 strength. Among these Category 5 storms were Hurricanes Katrina and Wilma, respectively the costliest and the most intense Atlantic hurricanes on record.


11 a.m.: The storm has strengthened into a tropical storm and named Katrina, becoming the 11th named storm of 2005. Its strongest winds are blowing at about 40 miles an hour.


5 p.m.: Katrina has strengthened into a Category One hurricane with winds up to 75 miles an hour. The storm is about to make landfall.

7 p.m.: The eye of Hurricane Katrina comes ashore in South Florida. The storm's top winds are 80 miles an hour.


1 a.m.: Katrina weakens and is reclassified as a tropical storm. Its strongest winds have reduced to 70 miles an hour.

3 a.m.: The storm starts strengthening almost immediately as it touches the warm waters of the Gulf of Mexico.

5 a.m.: Katrina re-intensifies into a hurricane. Its strongest winds are about 75 miles an hour.

11:30 a.m.: The National Hurricane Center reports that the hurricane is strengthening rapids as it crosses the Gulf of Mexico's very warm waters. In only a few hours, the storm's strongest winds have increased to about 100 miles an hour.

During the day: Governors Kathleen Blanco of Louisiana and Haley Barbour of Mississippi declare states of emergency in their respective states.

11 p.m.: The National Hurricane Center predicts that Katrina will become a major hurricane by the time it reaches the central Gulf of Mexico.


5 a.m.: Katrina's strongest winds have reached 115 miles an hour, making it a Category Three hurricane.

5 pm.: New Orleans Mayor Ray Nagin calls for a voluntary evacuation of New Orleans.


2 a.m.: Hurricane Katrina's winds have increased to 145 miles an hour, making it a Category Four storm.

9:30 a.m.: New Orleans Mayor Ray Nagin issues a mandatory evacuation order. Tens of thousands of New Orleans residents begin streaming out of the city, but many of the carless, homeless, aged and sick cannot evacuate.

"We're facing the storm most of us have feared," Nagin said. "This is going to be an unprecedented event."

11 a.m.: Hurricane Katrina has mushroomed into one of the most powerful hurricanes ever to form in the Atlantic. The storm's strongest winds are blowing at about 175 miles an hour, making it a Category Five storm.

5 p.m.: The National Hurricane Center describes Katrina as a "potentially catastrophic" hurricane.

"Some levees in the greater New Orleans area could be over-topped," the center warns. "Significant storm surge flooding will occur elsewhere along the central and northeastern Gulf of Mexico coast."

Late Sunday night: Thousands of New Orleans residents who are unable to leave town or have chosen not to leave seek shelter in the Louisiana Superdome, designated a “refuge of last resort” by Mayor Nagin.


2 a.m.: Hurricane Katrina turns north toward the Louisiana coast, but the storm's strongest winds have diminished slightly to about 155 miles an hour. The center of the storm is about 130 miles from New Orleans. A weather buoy about 50 miles east of the Mississippi river's mouth reports waves at least 40 feet (12 meters) high.

5 a.m.: The hurricane's strongest winds are now about 150 miles an hour, and its eye is about 90 miles from New Orleans.

7 a.m.: Hurricane Katrina's eye is about to come ashore in Plaquemines Parish, Louisiana. The hurricane's strongest winds are about 145 miles an hour. The eye is about 70 miles from New Orleans.

8 a.m.: Mayor Ray Nagin reports that water is flowing over one of New Orleans's levees.

9 a.m.: The eye is about 40 miles (65 kilometers) from New Orleans and is expected to pass just to the east of the city. The storm's strongest winds are about 135 miles an hour.

11 a.m.: The hurricane's eye comes ashore again near the Louisiana-Mississippi border. The storm's strongest winds are about 125 miles an hour. Katrina's front-right quadrant—which contains its strongest winds and peak storm surge—slams into Biloxi and Gulfport, Mississippi, with devastating force, destroying much of both cities.

Meanwhile, a major levee in New Orleans has failed. Water is pouring through the 17th Street Canal, and the city is beginning to flood.

1 p.m.: Hurricane Katrina continues to weaken as it moves farther inland. Its strongest winds are about 105 miles an hour.

3 p.m.: The hurricane’s winds are down to about 95 miles an hour.


11 a.m.: The National Hurricane Center issues its last advisory on the storm that once was Hurricane Katrina. The storm has maximum winds of about 35 miles an hour, and its center is dumping heavy rainfall on Tennessee.

During the day: Flood waters continue to pour into New Orleans from breaks in the city's levees.


During the day: Health and Human Services Secretary Michael O. Leavitt declares a public health emergency in Louisiana, Mississippi, Alabama, and Florida. Meanwhile, Louisiana Governor Kathleen Blanco orders that all remaining residents leave New Orleans, but buses and trucks aren't available to carry out the order.


2 p.m.: On national television New Orleans Mayor Ray Nagin issues a "desperate SOS" for help from the federal government. Nagin says there's no food for those who took shelter at the Louisiana Superdome and New Orleans convention center.


During the day: A convoy of U.S. National Guard troops and supply trucks arrives in New Orleans and distributes food and water to residents stranded at the Superdome and convention center. Congress approves 10.5 billion dollars (U.S.) in aid for Hurricane Katrina rescue and relief, and President George W. Bush signs the bill.


National Geographic