The climate of Fort-de-France is humid tropical, characterized by high average temperatures year-round (26.5 °C) and heavy precipitation (1,950 mm annually). However, the warmest monthly averages occur from August to October (31 °C daytime highs, 24–25 °C nighttime lows), while the coolest months are January and February (29 °C daytime highs, 22 °C nighttime lows). Like all of Martinique, Fort-de-France is influenced by the trade winds—the easterlies—whose general circulation determines the rainfall seasons. Thus, two main seasons are distinguished: •
Carême (February to April): the drier season, during which the trade winds carry less moisture (average monthly rainfall of 60–90 mm) and the sky is relatively clear; very fine days are common, though occasional showers still occur. •
Hivernage (the rainy season, July to October): the warmer and wetter season, with more frequent and more intense showers. However, between disturbances the weather is fair, the sky lightly clouded, and the trade winds weak. Hivernage corresponds to the tropical cyclone season. Among the most violent or devastating storms were the cyclone of 19 August 1891, which caused the deaths of 400 people in Fort-de-France (1,000 in Martinique as a whole) and destroyed most of the hospital and the Balata military camp. During
Hurricane Allen on 3–4 August 1980, wind gusts reached 167 km/h at Desaix, and 159 mm of rainfall were recorded in 18 hours. During
Hurricane Edith on 25 September 1963, the flow of the Rivière Madame reached 150 m³/s, whereas it normally ranges from 20 m³/s in flood periods to 0.050 m³/s during low-water periods. The interseason periods (November–January, May–June) have intermediate climatic characteristics, but may be marked by exceptional events. For example, due to the heavy rainfall of 4–5 May 2009, the total precipitation for May 2009 was the highest recorded for that month in fifty years in Fort-de-France—three times the average volume—leading to major flooding. One consequence of the mountainous terrain that dominates much of the territory of Fort-de-France, combined with episodes of heavy rain, is slope instability, resulting in landslide risks. Because temperatures decrease with altitude, middle- and upper-class residents have sought these more ventilated, cooler areas to build their homes, such as in Balata, Tivoli, La Redoute, or Haut Didier. Additionally, vegetation and forested areas remain prominent within the city, especially on the northern slopes. The mesophilic vegetation of the lower slopes gives way to hygrophilic vegetation (forests with vines and large trees) above 700 m. Moreover, many houses surrounded by gardens contain species that can supplement the diet of urban Foyalais, such as breadfruit trees, mango trees, and coconut palms.{{cite web == Demography ==