Haiti, occupying the western third of the island of Hispaniola, has a climate classified broadly as Tropical Maritime. The weather is generally warm year-round and heavily influenced by the surrounding Caribbean Sea and its associated moisture. The country’s varied landscape, however, introduces significant local complexity to this general pattern. The climate maintains high temperatures with minimal annual variation, but is strongly defined by its precipitation cycles and susceptibility to oceanic weather systems.
Defining Characteristics and Regional Variations
Lowland coastal areas, including the capital Port-au-Prince, experience consistently high temperatures with minimal seasonal variation. Average temperatures typically range from the low 70s to the mid-90s Fahrenheit (23°C to 35°C) throughout the year. The difference between the average temperature of the warmest month (July) and the coolest month (January) is relatively small due to the lack of a distinct thermal winter.
Humidity is a defining characteristic, frequently making the air feel muggy or oppressive, especially near the coast. Elevated moisture levels, maintained by proximity to the sea, mean the muggiest conditions prevail for much of the year, typically from late March through December.
The mountainous interior creates dramatic microclimates that contrast sharply with the coastal heat. As altitude increases, temperatures drop significantly, resulting in cooler, more temperate conditions in the highlands. For example, the village of Kenscoff, at 4,700 feet, averages around 60°F (16°C), substantially lower than the coast. These high-altitude regions can even experience frost during the winter months.
The Annual Cycle of Wet and Dry Seasons
Seasonality in Haiti is defined by the distinct cycle of precipitation, characterized by two separate rainy seasons. The first, shorter period of increased rainfall occurs in the spring, generally spanning from April to June.
The second, often more intense rainy period takes place during the autumn, usually lasting from August through November. These periods feature heavy, tropical downpours, with May and October frequently recording the highest monthly precipitation averages. Rainfall distribution is highly variable across the country, with coastal areas in the west, such as Port-au-Prince, being relatively drier compared to the northern and eastern mountain slopes.
The intervening months constitute the relatively dry seasons, with the most pronounced dry period occurring between December and March. Although designated as “dry,” the climate remains tropical and humid, and occasional showers are still possible. The significantly reduced rainfall during this time makes it the least humid period and the most popular for outdoor activities.
Vulnerability to Extreme Weather Events
Haiti’s geographical location places it directly in the Atlantic hurricane belt, making it highly susceptible to tropical cyclones and hurricanes. The Atlantic hurricane season officially runs from June 1st to November 30th, covering a six-month period when warm sea surface temperatures fuel storm formation. The peak of this activity typically occurs between late August and late September, directly overlapping with the country’s second rainy season.
The warm waters surrounding the island, which can exceed 84°F (29°C) during the summer and fall months, provide the energy needed for these systems to develop. The mountainous terrain significantly amplifies the destructive potential of heavy rainfall events. When tropical storms or hurricanes make landfall, the steep, deforested slopes increase the risk of massive landslides and intense flash flooding in the lowlands.
Beyond cyclones, the climate system also includes periodic risks of localized drought, which can severely impact agricultural productivity and water resources. Conversely, the sporadic, heavy rainfall events that follow dry spells can lead to devastating runoff and soil erosion, demonstrating the dual climate hazards faced by the nation.