The Caribbean islands, a vast archipelago stretching between the Americas, are defined by a singular, warm, and distinctly tropical climate. This region borders the Atlantic Ocean to the east and the Gulf of Mexico to the northwest, placing it firmly within the equatorial zone. The weather is consistently warm, making the Caribbean a year-round destination. The climate is shaped by its geographical position, creating predictable warmth across the islands.
Defining the Overall Caribbean Climate
The baseline weather experience across the Caribbean is one of perpetual summer, with consistently high temperatures and minimal seasonal variation. Average temperatures generally range between 25°C and 32°C (77°F to 90°F) throughout the year. The annual temperature range is small, often less than 5°C, especially in the southern islands closer to the equator. This stability results from the region’s latitude, which ensures high solar insolation year-round.
Consistent high humidity is a permanent characteristic of the Caribbean climate, typical of the tropical zone. Most islands fall under the Köppen classification of Tropical Monsoon (Am) or Tropical Rainforest (Af), signifying warm temperatures and high precipitation. Sea surface temperatures are equally stable and warm, typically remaining between 25°C and 32°C. This warm ocean water helps moderate air temperature and contributes significant moisture to the atmosphere, maintaining high humidity levels.
The Two Distinct Seasons
The annual weather cycle is marked by distinct shifts in precipitation, dividing the year into two primary seasons. The Dry Season typically runs from mid-December through April, offering the most consistently pleasant weather. This period is characterized by lower humidity, clear skies, and less frequent rainfall, making it the peak time for tourism. During the dry months, rainfall is minimal, and the atmosphere feels breezier and less oppressive.
The Wet Season, also referred to as the rainy or green season, generally spans from May or June to November. Temperatures remain high, but the humidity increases noticeably, making the air feel heavier. Rain typically occurs in short, intense bursts, often in the late afternoon, rather than continuous downpours. This increased precipitation fosters the lush, vibrant green landscapes for which many Caribbean islands are known.
Major Geographic and Atmospheric Influencers
The Caribbean climate is largely governed by the consistent presence of the Northeast Trade Winds, which are permanent east-to-west prevailing winds in the equatorial region. These winds blow almost constantly from the northeast, acting as a natural air conditioner that mitigates the tropical heat. As the trade winds travel across the Atlantic Ocean, they pick up considerable moisture, delivering warm, humid air to the eastern sides of the islands. The consistent movement of these winds also helps to steer weather patterns.
Warm ocean currents play a significant role in regulating the region’s temperature and atmospheric moisture. The Caribbean Current, a continuation of the Atlantic South Equatorial Current, flows northwestward through the Caribbean Sea. This warm current transports immense volumes of water, contributing to consistently high sea surface temperatures. The warm waters provide the heat and moisture necessary to fuel the tropical atmosphere.
Tropical Storms and Hurricanes
A defining feature of the Caribbean’s weather cycle is the annual Atlantic Hurricane Season, which officially runs from June 1st to November 30th. This period coincides with the Wet Season, as high sea surface temperatures and atmospheric instability create conditions conducive to storm development. The climatological peak occurs between mid-August and mid-October, centered around September 10th. During this peak, the difference between air and sea surface temperatures is greatest, providing maximum energy for storm intensification.
Tropical cyclones begin as tropical depressions, which are organized systems of clouds and thunderstorms with defined surface circulation and maximum sustained winds below 39 miles per hour (mph). Once sustained winds reach 39 mph, the system is classified as a tropical storm and is given a name. A system becomes a hurricane when its sustained winds reach 74 mph or higher, classifying it on the Saffir-Simpson Hurricane Wind Scale. The general path for many storms involves moving west-northwest across the main development region.
Regional Climate Variations Across the Islands
While the overall climate is tropical, the specific weather experience varies significantly across the islands due to topography and location. The distinction between Windward and Leeward Islands is based on their exposure to the prevailing Northeast Trade Winds. The Windward Islands, such as Dominica and Saint Lucia, face the trade winds directly and are generally wetter and more verdant. The moisture-laden air is forced upward by mountainous terrain, leading to orographic rainfall and lush rainforests on the wind-facing slopes.
In contrast, the Leeward Islands, including Aruba, Curaçao, and Bonaire, are downwind or in the rain shadow, resulting in drier, more arid conditions. These islands experience less frequent rainfall and have a more sun-drenched environment. Large, mountainous islands like Hispaniola or Jamaica exhibit distinct microclimates, where coastal areas are hot and humid while higher elevations experience cooler temperatures and higher rainfall. Smaller, flatter islands, such as the Bahamas, tend to have a more uniform climate characterized by lower overall rainfall and consistent sea breezes.