San Juan Temperature by Month

San Juan in Trinidad, Trinidad & Tobago enjoys a stable climate, with daytime temperatures staying close to 29°C (84°F) throughout the year. Explore the full monthly breakdown below.

With minimal seasonal shifts, San Juan experiences a constant climate year-round. Maximum daytime temperatures range from a very warm 30°C (86°F) in September to a comfortable 28°C (82°F) in January. At night, temperatures range from 26°C (79°F) in September to 24°C (75°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in San Juan by month:

The coolest part of the day is typically between 4 AM and 6 AM, while 3 PM is usually the warmest, when solar heating is at its peak. September, the city's warmest month, averages 197 hours of sunshine.

The chart below shows the average temperature throughout the year:

San Juan's average annual maximum temperature is 29°C (84°F). To put that in context, here's how it compares to a few well-known destinations:

Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.

Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.

Osaka, Japan averages 22°C (72°F) annually, with hot humid summers, mild winters, and pleasant spring and autumn seasons.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In San Juan, January is the coolest month, with average highs of 28°C (82°F) and humidity around 81%, considered very high. In September, the warmest month, temperatures average 30°C (86°F) with 84% humidity, conditions that feel very high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on San Juan's weather, including monthly rainfall, sunshine hours, and humidity, visit our San Juan climate page.