The Atlantic hurricane season runs from June to November in the Caribbean, posing a threat to coastal communities when tropical storms and hurricanes generate storm surges and trigger landslides and flash floods.

An average season has 10 tropical storms, of which six strengthen into hurricanes. Elsewhere in Latin America, torrential rains between December and May can swamp agricultural land, destroy livelihoods, damage homes and services and force mass evacuations.

In 2009, floods and mudslides in northeastern Brazil killed around 40 people, left hundreds of thousands homeless and devastated swathes of farmland.

The flooding - said to be the worst in recent memory - has washed out bridges and roads, submerged homes and destroyed crops, according to aid workers.

Aid agencies say there are fears of food shortages and growing risks of outbreaks of water-borne diseases and insect infestations.

In early 2008, devastating floods hit Bolivia, Ecuador and Peru as a weather abnormality known as La Nina brought some of the heaviest rains in a quarter-century, swelling rivers and bursting banks. Ecuador and Peru both declared states of emergency.

Meaning "little girl" in Spanish, La Nina is an unusual cooling of Pacific Ocean surface temperatures that can trigger more hurricanes and worse rains in many places.

In late 2008, serious flooding also affected Honduras and Colombia.

Death tolls from floods have generally fallen in recent years as countries become more adept at disaster prevention, although experts warn that more people are likely to be affected in future as global warming generates more and bigger floods.

British researchers say they have shown that a half-degree Celsius temperature rise in the Atlantic Ocean can fuel a 40 percent increase in hurricanes. Other factors increasing flood risks include deforestation and rapid urban growth.