The ninth named storm and the sixth hurricane of the season, Irene developed in the western Caribbean Sea on October 13 from a tropical wave.

[1] It later dropped 10 to 20 inches (254 to 508 millimetres) of rainfall in the Miami metropolitan area, causing urban flooding unseen since Hurricane Dennis in 1981.

In North Carolina and Virginia, Irene produced over 10 inches (250 mm) of rain, adding more flooding after previous hurricanes Dennis and Floyd.

The depression strengthened further over the favorable conditions present in the Caribbean Sea, and attained tropical storm status six hours later, when it was assigned the name Irene.

[1] Operationally, the National Hurricane Center (NHC) continued to classify the system as a low-pressure area until 15:00 UTC on October 13, by which time it had already reached tropical storm status.

[3] Tropical Storm Irene strengthened as it moved northward and reached sustained winds of 70 mph (110 km/h) early on October 14.

Irene continued to move towards the north-northeast, crossed over the western portion of the Isla de la Juventud as a strong tropical storm, and around 19:00 UTC, it struck mainland Cuba near Batabanó in Mayabeque Province.

The cyclone emerged into the Straits of Florida several hours later and resumed intensification, and Irene attained hurricane status early on October 15.

[1] Despite Irene strengthening prior to landfall in the state, wind shear caused deep convection to remain mostly displaced to the storm's east side in a semicircular pattern around the center.

However, as the hurricane moved northeastward across southeast Florida, deep convection noticeably shifted farther west, likely as a result of a westward movement of the low-level convergence zone due to increased friction.

While interacting with very warm ocean waters and the upper-level trough on the following day, Irene rapidly intensified, reaching maximum sustained winds of 110 mph (180 km/h) with a minimum barometric pressure of 958 mbar (28.3 inHg), a Category 2 hurricane, at 07:56 UTC.

Workers protected tobacco leaves by moving them to sealed warehouses, and transported cattle and livestock to higher ground.

[1] Initially, forecasters predicted Irene to parallel the west coast of Florida, weakening to a tropical storm before making landfall on the west-central portion of the state.

However, when a more eastward track became evident,[9] officials in Monroe, Charlotte, Lee, and Manatee Counties issued evacuation orders for people in mobile homes and recreational vehicles.

However, when the track shifted further to the east, mandatory evacuation orders were issued for coastal areas of North Carolina, with tens of thousands removed from their homes.

The evacuation order included several beach towns; those living in low-lying areas and mobile homes were advised to seek shelter.

[1] Abnormally high tides generated by the storm overtopped the Malecón seawall in Havana, inundating nearby low-lying areas and prompting the evacuation of several hundred people.

[16] Because Irene continued northeastward after making landfall at Cape Sable, Southwest Florida reported little impact, mostly limited to a few downed trees, palm frons, and power lines in Collier and Lee counties.

[19] Strong wind gusts left 700,000 people without power from Miami to West Palm Beach, including the National Hurricane Center.

[29] A U.S. Sugar processing mill in Bryant suffered about $4 million in damage after winds demolished two cooling towers and toppled some of the facility's walls.

Strong north winds and high seas severely destroyed or damaged docks in the Indian River Lagoon.

[33] Much of southern St. Johns County experienced additional severe erosion in the wake of Hurricane Floyd,[24] leaving minor damage to some structures.

[1] The rainfall caused severe river flooding in North Carolina, many of which had not receded from Hurricane Floyd's passage less than a month earlier.

[42] Hurricane Irene also produced heavy rainfall in southeastern Virginia of up to 12 inches (300 mm) in Chesapeake,[1] where floodwaters entered some homes.

Additionally, widespread street flooding occurred, with a total 17 sections of road closed in Southampton County and Suffolk alone.

[47] As an extratropical cyclone, the remnants of Irene brought gusty winds, heavy rains, and snow to Newfoundland, especially the central and western parts of the island.

The Cuban Red Cross mobilized over 4,500 volunteers to the affected areas to provide first aid to injured, distribute meals and medical supplies, and collaborate with blood banks.

[6] The government-controlled media broadcast system guaranteed repair items, though many people remained in damaged houses in the weeks after the storm.

The declaration allowed affected businesses and homeowners to apply for federal assistance, such as money for temporary housing, minor home repairs, or disaster-related expenses.

[50] Due to the crop damage, the U.S. Department of Agriculture declared Broward, Collier, Miami-Dade, and Monroe counties as disaster areas.