Emily attained maximum sustained winds of 260 km/h (160 mph) on 16 July while passing southwest of Jamaica, which at the time made it the strongest Atlantic hurricane before the month of August.

While moving through the Lesser Antilles, the hurricane produced strong winds and heavy rainfall that caused flooding and landslides across several islands.

Ahead of the hurricane's first landfall in Mexico, officials ordered evacuations for popular tourist areas along the eastern Yucatán Peninsula.

[1] The origins of Hurricane Emily were from a mesoscale convective system that developed over Ethiopia in eastern Africa, which evolved into a tropical wave that moved westward.

[3] The convection, or thunderstorms, became better organized on 9 July, prompting the National Hurricane Center (NHC) to include the system as a potential area for tropical cyclone development.

[3][12] Emily's rapid intensification was potentially caused by a plume of air from the Amazon and Orinoco rivers interacting with the warm waters of the Caribbean.

[23] At 12:00 UTC on 21 July, Emily made its final landfall in the Mexican state of Tamaulipas near San Fernando, or about 140 km (85 mi) south of Brownsville, Texas, with winds of 205 km/h (125 mph).

The hurricane rapidly weakened over the mountainous terrain of the Sierra Madre Oriental, quickly dropping to tropical storm status and dissipating late on 21 July over northern Mexico.

[3] Still recovering from Hurricane Ivan a year prior, which damaged or destroyed approximately 90 percent of housing,[24] residents in Grenada took quick action to prepare for Emily, including declaring a state of emergency.

The Jamaica Red Cross moved supply stockpiles originally intended for Dennis-related relief to southern areas of the island in preparation for Emily.

[49] Preparations to evacuate thousands of residents from coastal communities (up to 1 km (0.62 mi) inland) in the eastern Yucatán Peninsula began on 16 July, including the islands of Cozumel, Holbox, and Mujeres.

[53] The states of Yucatán and Quintana Roo issued the highest level of alert on 17 July, considering Emily an "extremely dangerous" storm, and likening its trajectory to Hurricane Gilbert in 1988.

[51] No alcohol was sold in Cancún for 36 hours prior to the arrival of the storm, in an attempt to avoid drunken tourists being injured during the night.

[60] The Costa Rican National Meteorological Institute advised residents in high-risk areas to be alert and to avoid venturing outside in the event of rainfall.

[52] Early fears of Emily's potential disruption to oil production in the Gulf of Mexico contributed to a one-dollar rise in prices by 13 July, bringing the cost of a barrel to over US$60.

[62] On 17 July, the American Red Cross began preparations to open shelters and had emergency supplies deployed for rapid distribution in South Texas.

The rains caused widespread landslides, particularly in mountainous areas of northern Grenada as well as vegetation damaged by Hurricane Ivan ten months prior.

[83] In the general hospital in Grenada's capital, St. George's, the hurricane damaged windows and caused flooding that forced the evacuation of the female medical ward.

[27] The combination of strong winds and flooding rains disrupted the agriculture industry's recovery after Ivan, after Emily knocked down trees and eroded away soil.

Cash crops, including corn and pigeon peas, were largely lost, while breadfruit, nutmeg, and cocoa trees were negatively impacted.

[69][84] In the small island of Carriacou, north of Grenada, the hurricane severely damaged the roof of Princes Royal Hospital, forcing patients to evacuate.

[69] While passing south of Jamaica, Emily dropped heavy rainfall, reaching 392 mm (15.43 in) at Potsdam in Saint Elizabeth Parish.

[46] While passing south of Cuba, the outer rainbands of Emily produced heavy rainfall and coastal flooding on Isla de la Juventud.

[51] During its final landfall in northeastern Mexico, a weather station in San Fernando, Tamaulipas, 55 km (30 mi) inland, recorded wind gusts of 166 km/h (97 mph).

Floods also washed out a river in Guadalupe along the Río Santa Catarina, causing a natural gas leak that was contained a few hours later.

[51] While making its final landfall in northeastern Mexico, Emily's outer rainbands spread into South Texas, with peak wind gusts of 102 km/h (63 mph) recorded in Brownsville.

Heavy rains caused flash flooding, closing a portion of State Route 4, and shutting down several businesses in McAllen.

[81] The Pan American Disaster Response Unit (PADRU) sent an airplane to the Haitian Red Cross on 17 July with blankets and cleaning supplies.

In Quintana Roo, the country's Fondo de Desastres Naturales (Natural Disaster Fund) helped finance the construction of 167 homes away from high-risk areas.

More than 1,700 health workers visited shelters and homes to prevent the further spread of disease, with the primary illness being acute respiratory infections.