Dominica has a tropical wet climate with characteristically warm temperatures and heavy rainfall. Excessive heat and humidity are tempered somewhat by a steady flow of the northeast trade winds, which periodically develop into hurricanes. The steep interior slopes also alter temperatures and winds. Temperature ranges are slight. Average daytime temperatures generally vary from 26°C in January to 32°C in June. Diurnal ranges are usually no greater than 3°C in most places, but temperatures dipping to 13°C on the highest peaks are not uncommon.

Most of the island's ample supply of water is brought by the trade winds. Although amounts vary with the location, rain is possible throughout the year, with the greatest monthly totals recorded from June through October. Average yearly rainfall along the windward east coast frequently exceeds 500 centimeters, and exposed mountainsides receive up to 900 centimeters, among the highest accumulations in the world. Totals on the leeward west coast, however, are only about 180 centimeters per year. Humidities are closely tied to rainfall patterns, with the highest values occurring on windward slopes and the lowest in sheltered areas. Relative humidity readings between 70 percent and 90 percent have been recorded in Roseau.

Hurricanes and severe winds, most likely to occur during the wettest months, occasionally are devastating. The most recent hurricanes of note were David and Frederick in August 1979 and Allen in August l980. The 1979 hurricanes caused over 40 deaths, 2,500 injuries, and extensive destruction of housing and crops. Many agricultural commodities were destroyed during the 1980 storm, and about 25 percent of the banana crop was demolished by strong winds in 1984.

Data as of December 1989

NOTE: The information regarding Dominica on this page is re-published from The Library of Congress Country Studies and the CIA World Factbook. No claims are made regarding the accuracy of Dominica Climate information contained here. All suggestions for corrections of any errors about Dominica Climate should be addressed to the Library of Congress and the CIA.