Port of Spain is characterized by a consistent tropical heat where thermal variation is almost non-existent throughout the year. WeatherBox data indicates that the difference between the annual minimum and maximum mean temperatures is only 1.9°C (3.4°F), creating a stable, often oppressive thermal environment. The daily temperature swing is equally minimal, with the average intraday range reaching just 1.4°C (2.5°F), meaning there is little relief from the warmth even at night. Even during the hottest periods, the temperature rarely exceeds 29.4°C (84.9°F), but the atmosphere remains heavy as lows rarely drop below 23.8°C (74.8°F). The most intense heat is typically recorded when the average daily high reaches 28.3°C (82.9°F).
While the heat remains constant, moisture levels fluctuate between arid dry spells and heavy tropical downpours. The driest phase occurs early in the year, where monthly rainfall drops to an average of 31 mm (1 in). During this clearer season, solar intensity is extreme, and the average peak UV Index is 11.8. In contrast, the wet season brings dense cloud cover—obscuring the sky 85.8 of the time—and frequent precipitation, with the highest monthly rainfall averaging 153 mm (6 in). The air remains thick year-round, as humidity levels never fall into a comfortable range, eventually peaking at 83.7.
Persistent air currents help mitigate the intense humidity, with prevailing winds blowing from the E for 40.6 of the year. These breezes are strongest early in the year, with average speeds reaching 25.6 km/h (15.9 mph), though gusts rarely exceed 33.7 km/h (20.9 mph). According to WeatherBox, the combination of high moisture and steady trade winds characterizes the sensory experience of the location. View the advanced weather charts on WeatherBox to see detailed breakdowns of hourly temperature fluctuations and seasonal precipitation graphs.
