A hurricane packing 130 kilometer (80 mile) per hour winds and heavy rain made landfall in Central America near Belize's capital, where officials warned of likely flooding and damage to homes Thursday.
Earl swept in from the Caribbean at hurricane strength to strike just south of Belize City, population 60,000, around midnight Wednesday (0600 GMT Thursday), according to the US National Hurricane Center (NHC).
The storm weakened as it moved inland, and by 1200 GMT the NHC had downgraded it from a hurricane to a tropical storm with 65 mile (105 kilometer) per hour winds.
Belize's National Emergency Management Organization had warned of a threat of flashfloods and mudslides and flooding in low-lying areas.
Eight to 12 inches of rainfall were forecast for Belize, Guatemala, and southern Mexico through Friday. Airports in the area were closed.
Earl was expected to dissipate further as it moves across northern Guatemala and southern Mexico, the NHC said.
The Mexican authorities took no chances, evacuating 300 families living close to a river along the border with Belize in the southeastern state of Quinta Roo for fear of flooding.
More than 750 shelters were readied in the state in preparation for expected high winds and fierce gusts.
Other southern Mexican states likely to be affected were Campeche, Tabasco and Yucatan.
In the northern Guatemala town of Puerto Barrios, a military commander, Colonel Nelson Tun, told AFP that "patrols in vulnerable areas" were being carried out.
"We have identified high areas to where the population can evacuate before possible flooding," he said.
Guatemala in particular is prone to rainy season flooding and mudslides that often prove fatal.
Guatemala's population, at 16 million, is much bigger than the 330,000 in Belize, Central America's only English speaking country.
Guatemala's president, Jimmy Morales, late Wednesday offered Belize humanitarian aid and shelters along the border if needed.
That gesture was significant after months of tensions between the two countries following a shooting death of a Guatemalan boy by a Belizean border patrol in April.
The fifth named tropical storm of the 2016 season, Earl strengthened to a Category 1 hurricane on Wednesday, according to the NHC. Winds initially measured at 120 kilometers per hour picked up just before landfall.
Category 1, the lowest of five grades on the hurricane scale, is described as having dangerous winds of between 119 and 153 kilometers per hour that can rip off roofs, bring down trees and cause extensive damage to power lines.
Belizean public and private sector workers were permitted to go to their homes Wednesday to secure property.
Officials warned that people living on the ground floor "will experience flooding" and some older wooden buildings would likely be destroyed.
The authorities have opened 29 shelters.