Hurricane Irma was a devastating tropical cyclone that impacted the entire state of Florida in September 2017. The storm was one of the most powerful hurricanes on record in the Atlantic basin. It ultimately struck the Florida Keys as a Category 4 major hurricane, becoming the first storm of that intensity to make landfall in the state since 2004. Its sheer size and prolonged wind field ensured a historic impact across nearly all of Florida’s 67 counties.
The Chronology and Intensity of Hurricane Irma
Hurricane Irma first reached Category 5 status on September 5, 2017, west of the Cape Verde Islands, with peak sustained winds reaching 180 miles per hour. The storm maintained this Category 5 intensity for an exceptional 78 consecutive hours, setting a record for the longest-lived Category 5 in the Atlantic basin outside of the Gulf of Mexico and Caribbean Sea. After making multiple landfalls across the Caribbean and Cuba, the storm weakened but re-intensified over the warm waters of the Florida Straits.
By the morning of Sunday, September 10, Irma had strengthened back into a Category 4 hurricane as it tracked toward the Florida Keys. The storm’s wind field was immense, with hurricane-force winds extending up to 80 miles from the center and tropical-storm-force winds spanning 220 miles. This size necessitated mandatory evacuations for millions of residents across the southern and coastal parts of the state.
Florida Landfall and Inland Path
The first Florida landfall for Hurricane Irma occurred at 9:10 a.m. EDT on September 10, 2017, striking Cudjoe Key in the Lower Florida Keys. At this time, the storm was classified as a powerful Category 4 hurricane, with maximum sustained winds estimated at 130 miles per hour. Following its initial impact, the storm briefly weakened due to friction with land but maintained major hurricane status.
Irma made its second and final official United States landfall later that same day at 3:35 p.m. EDT near Marco Island, on the southwestern coast of the mainland. The storm struck Marco Island as a high-end Category 3 hurricane with sustained winds of 115 miles per hour. From there, the hurricane tracked north-northwest, moving inland across the Florida peninsula.
The storm carried it between the major metropolitan areas of Tampa and Orlando, continuing north while rapidly weakening due to land interaction and increased wind shear. By the time the center of the storm was near Gainesville on the morning of September 11, it had been downgraded to a Tropical Storm, before exiting the state into Georgia later that day. Even as a weakening storm, its sheer size meant that hurricane-force wind gusts were recorded as far inland as Hendry County.
Immediate Impact and Recovery Needs
Hurricane Irma caused one of the largest power outages in United States history related to a tropical cyclone. At its peak, approximately 6.7 million electricity customers in Florida were without power, accounting for roughly 64% of the state’s total accounts. This loss of electricity was felt in all 67 counties, profoundly affecting critical infrastructure like communication networks.
The storm produced devastating storm surge and inland flooding, particularly in areas east of the track due to the massive wind field. In the Keys and Southwest Florida, storm surge inundation reached 5 to 6 feet above ground level in places like Goodland. Further north, the St. Johns River experienced significant flooding in Jacksonville, resulting in one of the worst flooding events in the city’s history.
In the initial recovery phase, the focus was on restoring power and clearing massive amounts of debris. Power was restored quickly for most customers, with the number of outages dropping from 64% to 18% within five days, but some isolated areas faced extended blackouts. In parts of the Florida Keys, power outages lasted as long as 20 days due to severe infrastructure damage. This widespread damage triggered a large-scale response involving numerous federal and state agencies, including FEMA, to coordinate aid and debris removal.