After crossing the Greater Antilles, the system began to organize over Cuba and was designated a potential tropical cyclone on August 2.

It moved northwards and gradually intensified into a Category 1 hurricane before making landfall near Steinhatchee, Florida, early on August 5.

Debby weakened once inland and began to slow down over the Southeastern United States, causing widespread flooding from heavy rain.

[6] As the disturbance moved westward it crossed over the Virgin Islands, Puerto Rico,[7] and Hispaniola, becoming increasingly defined by August 1.

[9] After that, the disturbance moved off the southern coast of Cuba and formed a closed circulation, allowing the NHC to upgrade and designate it as Tropical Depression Four at 03:00 UTC on August 3.

[10] The depression than crossed over the western part of Cuba and entered the Gulf of Mexico, where it further intensified into Tropical Storm Debby later on August 3.

[14] Turning northeastwards slightly in response to a trough in the Northeastern United States, Debby approached the Big Bend area as it peaked with sustained winds of 80 mph (130 km/h) and a minimum pressure of 979 millibars (28.9 inHg) early on August 5.

[17] The forward speed of the cyclone began to slow as the aforementioned trough moved off shore and left Debby in light steering currents.

[18] Debby moved offshore the coast of Georgia early on August 6 as a weak tropical storm, but eventually strengthened slightly to a secondary peak of 60 mph (97 km/h) as its broad nature prevented much in the way of intensification.

[49] Around 50 first responders from Frederick, Howard, and Montgomery counties in Maryland, as well as Washington, D.C., were deployed to Charleston to aid in search and rescue efforts.

[59] The New York Yankees postponed their August 9 game against the Texas Rangers until the following day due the forecasted inclement weather.

[61] The National Weather Service issued flood warnings for 33 municipalities in Puerto Rico, mostly in the eastern half of the island.

[65] Heavy rain, gusty winds and downed trees delayed dozens of trains in Mid-Atlantic and Northeastern United States on August 9.

[4] The outer bands of Debby began impacting Central and South Florida on August 3, bringing gusty winds and rainfall.

[75] Two people were killed and another were severely injured in a car accident in Dixie County due to the inclement weather caused by Debby.

[79] Debby washed ashore 25 packages of cocaine at a beach in the Florida Keys, worth over $1 million, which is believed to have originated from nearby countries in the Caribbean known for drug trafficking.

The Sarasota County Sheriff's Office recovered the vehicle and discovered the body of a 67-year-old man who went missing on August 6 during heavy flooding in the area.

[92] As part of the 2024 United States presidential election, Kamala Harris and her running mate Tim Walz planned to hold a political rally in Raleigh, North Carolina on August 8, as did Republican vice presidential nominee JD Vance; both rallies were postponed due to the hurricane.

[95] North Carolina governor Roy Cooper deployed around 350 soldiers with 17 water rescue teams to the eastern and central parts of the state.

[100] Three EF1 tornadoes occurred in the state; they knocked down trees and power poles and damaged numerous structures, including homes.

[102] Another EF1 tornado occurred northwest of Stanton, Delaware, where a store and a light pole at a strip mall were damaged and trees were snapped or uprooted.

[108] Heavy rainfall prompted flash flood emergencies for several towns in Steuben and Allegany counties in New York, where over 4 in (100 mm) of rain fell; those same alerts extended into Westfield, Pennsylvania as well.

[109] A high-end EF1 tornado struck the eastern part of Harrisburg, Pennsylvania, severely damaging structures and knocking down trees.

[113] On Long Island, tropical moisture enhanced by Debby resulted in flooding on August 6, with over 4 in (100 mm) of rain falling down.

[116] As the remnants of Debby passed through the inner United States on August 10, portions of the New England coastal region faced dangerous rip currents and swells, with the entire coastlines of Maine, Massachusetts, New Hampshire, and Rhode Island being issued a rip current statement by the National Weather Service.

Governor Phil Scott placed a Federal Emergency Declaration in the state prior to the arrival of Debby's remnants.

[141] In January 2025, the Insurance Bureau of Canada finalized the insurance damage caused by the remnants of Debby to be Can$2.7 billion (US$2 billion),[5] and Debby became the costliest weather event in Quebec history, and the costliest tropical cyclone in the country, surpassing the record held by Fiona two years ago.

They announced that they planned to distribute water bottles and clean-up kits to residents impacted by flash flooding on August 11–12.

A shelter was opened and operated by the Red Cross at Corning-Painted Post High School for flood victims until August 12.

Faith-based disaster relief organizations in Pennsylvania also mobilized to help assess damage and provide help to victims of Debby.