Port of Spain
Trinidad and Tobago
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Port of Spain, Trinidad and Tobago

The ancient building hosting the public library of the Port of Spain in Trinidad and Tobago, with palm trees outside
The ancient building hosting the public library of the Port of Spain in Trinidad and Tobago, with palm trees outside
The first month of the autumn, September, is still a tropical month in Port of Spain, Trinidad and Tobago, with temperature in the range of an average high of 32.2°C (90°F) and an average low of 23.1°C (73.6°F).

Temperature

In Port of Spain, the average high-temperature is relatively the same as in August - a still hot 32.2°C (90°F). In Port of Spain, the average low-temperature is 23.1°C (73.6°F).

Heat index

In September, the average heat index is calculated to a burning hot 46.9°C (116.4°F). Be wary - heat exhaustion and heat cramps are highly anticipated. With continued activity, heatstroke is very likely.
Note that heat index values are valued for light wind and location in the shade. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'felt air temperature', 'feels like', or 'apparent temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (wind, clothing, metabolic differences). Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

In Port of Spain, the average relative humidity is 84%.

Rainfall

In Port of Spain, during 16 rainfall days, 190.5mm (7.5") of precipitation is typically accumulated. In Port of Spain, during the entire year, the rain falls for 166 days and collects up to 1408mm (55.4") of precipitation.

Sea temperature

September is the month with the warmest seawater in Port of Spain, with an average sea temperature of 29°C (84.2°F).
Note: For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

In September, the average length of the day in Port of Spain is 12.2h.

Sunshine

In Port of Spain, the average sunshine is 6.6h.

UV index

Months with the highest UV index in Port of Spain are February through October, with an average maximum UV index of 12. A UV Index value of 11, and more, symbolizes an extreme health hazard from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: The daily maximum UV index of 12 interpret into the following advice:
Practice all essential precautions. Protection against sun damage is crucial. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Even on cloudy days, a sunscreen with a minimum 30 sun protection factor should be generously applied and frequently re-applied, including after every swim or outdoor exercise. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.

What is the temperature in September in Port of Spain?

The average high-temperature, in September, in Port of Spain, Trinidad and Tobago, is 32.2°C (90°F), while the average low-temperature is 23.1°C (73.6°F). The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), that represents influence of the relative humidity to air temperaure, in September is calculated to 46.9°C (116.4°F).

What is the average humidity in September in Port of Spain?

In Port of Spain, the average relative humidity in September is 84%.

How much does it rain in Port of Spain in September?

In September, the rain falls for 16 days. Throughout September, 190.5mm (7.5") of precipitation is accumulated.

When is the sea warmest in Port of Spain?

The month with the warmest seawater in Port of Spain, Trinidad and Tobago, is September, with an average sea temperature of 29°C (84.2°F).

What is the water temperature in September in Port of Spain?

In Port of Spain, the average seawater temperature in September is 29°C (84.2°F). For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

How many hours of daylight does Port of Spain have in September?

The average length of the day in September in Port of Spain, Trinidad and Tobago, is 12.2h.

How long on average sun shines in September in Port of Spain?

The average sunshine in September is 6.6h.

What are the months with the highest UV index in Port of Spain?

Months with the highest UV index in Port of Spain, Trinidad and Tobago, are February through October, with an average maximum UV index of 12.

How high is the UV index in September in Port of Spain?

In Port of Spain, the average daily maximum UV index in September is 12. A UV Index of 11, and more, symbolizes an extreme health threat from the exposure to the Sun's UV rays.
Average temperature in September - Port of Spain, Trinidad and Tobago
  • Average high temperature in September: 32.2°C

The warmest month (with the highest average high temperature) is May (33.1°C).
The month with the lowest average high temperature is January (28°C).

  • Average low temperature in September: 23.1°C

The month with the highest average low temperature is June (23.3°C).
The coldest month (with the lowest average low temperature) is January (17°C).

Average humidity in September - Port of Spain, Trinidad and Tobago
  • Average humidity in September: 84%

The month with the highest relative humidity is November (86%).
Months with the lowest relative humidity are March and April (77%).

Average rainfall in September - Port of Spain, Trinidad and Tobago
  • Average rainfall in September: 190.5mm

The wettest month (with the highest rainfall) is August (244mm).
The driest month (with the lowest rainfall) is March (16.9mm).

Average rainfall days in September - Port of Spain, Trinidad and Tobago
  • Average rainfall days in September: 16 days

The month with the highest number of rainy days is July (21 days).
Months with the lowest number of rainy days are March and April (6 days).

Average sea temperature in September - Port of Spain, Trinidad and Tobago
  • Average sea temperature in September: 29°C

The best month for swimming (with the highest average sea temperature) is September (29°C).
Coldest months (with the lowest average sea temperature) are February and March (26°C).

Average daylight in September / Average sunshine in September - Port of Spain, Trinidad and Tobago
  • Average daylight in September: 12.2h

Months with the longest days are June and July (Average daylight: 12.7h).
The month with shortest days is December (Average daylight: 11.5h).

  • Average sunshine in September: 6.6h

The month with most sunshine is February (Average sunshine: 8.3h).
The month with least sunshine is June (Average sunshine: 6.1h).

Average UV index in September - Port of Spain, Trinidad and Tobago
  • Average UV index in September: 12

Months with the highest UV index are February, March, April, May, June, July, August, September and October (UV index 12).
The month with the lowest UV index is December (UV index 9).