In October 1999, severe flooding affected portions of eastern Mexico and Central America. Rainfall in September preceded the primary event in Mexico, which moistened soils. On October 4, Tropical Depression Eleven developed in the Gulf of Mexico, which drew humidity from the gulf and the Pacific Ocean to produce torrential rainfall in mountainous regions of eastern Mexico, reaching 43.23 in (1,098 mm) in Jalacingo, Veracruz. This was the third-highest tropical cyclone-related rainfall total in Mexico from 1980–2006, and the event caused the highest rainfall related to tropical cyclones in Veracruz, Hidalgo, and Puebla. In some locations, the daily rainfall represented over 10% of the annual precipitation total. The heaviest rainfall occurred in mountainous regions that were the mouths of several rivers. A broad trough absorbed the depression on October 6, and rainfall continued for the next few days. Additional rainfall occurred in Tabasco state on October 18. The floods were estimated as a 1 in 67 year event in one location, although such floods are expected to affect eastern Mexico twice per century, the last time being 1944.

The 1999 Atlantic hurricane season was a fairly active season, mostly due to a persistent La Niña that developed in the latter half of 1998. It had five Category 4 hurricanes – the highest number recorded in a single season in the Atlantic basin, previously tied in 1933 and 1961, and later tied in 2005 and 2020. The season officially began on June 1, and ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. The first storm, Arlene, formed on June 11 to the southeast of Bermuda. It meandered slowly for a week and caused no impact on land. Other tropical cyclones that did not affect land were Hurricane Cindy, Tropical Storm Emily, and Tropical Depression Twelve. Localized or otherwise minor damage occurred from Hurricanes Bret, Gert, and Jose, and tropical storms Harvey and Katrina.