The climate of Trinidad and Tobago is tropical, hot all year round, with little seasonal variation: the maximum temperatures are about 30/32 °C (86/90 °F) in the coolest period, from December to February, and a little higher in the rest of the year. September and October are the most sweltering months, January and February the least hot. Luckily, the northeast trade winds blow all year round, tempering the heat.
The islands forming the archipelago of Trinidad and Tobago, namely the two main islands of the same name plus some smaller islands (including Little Tobago), are the southernmost of the Lesser Antilles, however, some geographers do not consider them as part of the said Lesser Antilles because of their eccentric position, together with Barbados.
Here are the average temperatures of the capital, Port of Spain.
Port of Spain - Average temperatures
Min (°C)202021222323232323232221
Max (°C)313232333332313232323231
Min (°F)686870727373737373737270
Max (°F)889090919190889090909088

The main difference in the climate is found in the rainfall: there is a rainy season, which runs from June to December, and a relatively dry season, which runs from January to mid-April.
Rainfall is abundant: in Port of Spain, on the island of Trinidad, it's around 1,700 millimeters (67 inches) per year, with more than 100 mm (4 in) per month from May to December, and more than 200 mm (8 in) it the three rainiest months, i.e. June, July and August. The driest months are February, March and April, with an average of 30/40 mm (1.2/1.6 in) of rain per month.
Here is the average precipitation.
Port of Spain - Average precipitation

Scarborough, on the island of Tobago, receives 1,500 mm (60 in) of rain per year: even here precipitation exceeds 100 mm (4 in) per month from June to December, but it exceeds 200 mm (8 in) only in October and November.
In the interior of both islands, there are some elevations: in Trinidad, they are found in the northern part, where there are two peaks reaching 1,000 meters (3,300 feet), El Cerro del Aripo and El Tucuche, while Tobago is crossed by a chain of hills and low mountains in the interior, reaching 640 meters (2,100 feet). On the slopes of both islands, the climate is even rainier, especially those facing north, where rainfall even reaches 3,800 millimeters (150 inches) per year.
Since the rains occur throughout the year especially in the form of showers or thunderstorms, they do not reduce too much the amount of sunshine, which is good throughout the year, especially along the coast, as can be seen in the following table.
Port of Spain - Sunshine


The sea in Trinidad and Tobago is warm enough to swim in throughout the year: the water temperature ranges from 26 °C (79 °F) in February and March, to 29 °C (84 °F) in September. Here are the average sea temperatures.
Port of Spain - Sea temperature
Temp (°C)272626272727282829282827
Temp (°F)817979818181828284828281


Trinidad and Tobago are in theory just outside of the hurricane belt, and in fact they are seldom, if ever, affected, especially Trinidad, which is even more sheltered because of its southern position. However, we recall that the hurricane season in the Caribbean goes from June to November, though they are more likely from August to October. Some hurricanes and tropical storms that hit the islands were Hurricane 2 (or Trinidad Hurricane) of July 1933 (the only truly destructive one), Tropical Storm Alma in August 1974, Tropical Storm Bret in August 1993, Hurricane Ivan in September 2004, and Hurricane Felix in September 2007.

Best Time

The best time to visit Trinidad and Tobago is from January to April, which is by far the driest of the year. Since these islands are almost always outside of the hurricanes paths, in theory you can also choose the summer, keeping in mind that it is very rainy, and even muggy. December is still rainy, but it's outside of the period of hurricanes, and also a little cooler.

What to pack

All year round: pack light clothes, of natural fabric, and possibly a light sweatshirt and a light raincoat for thunderstorms, especially from June to December. A light sweatshirt for the evening from December to March.
When going to the reef, you can bring snorkeling equipment, including water shoes or rubber-soled shoes.