On Monday 27th April 2020, hot temperatures were prevalent across parts of Trinidad, with uncomfortably warm temperatures elsewhere.
Across most of the country, temperatures between ranged between 31.0°C and 33.0°C, with isolated areas between 33.0°C and 35.0°C, mainly across Trinidad. In urban areas and areas where development is prevalent, temperatures trended higher.
The maximum recorded temperature occurred at the Piarco International Airport, coming in at a scorching 34.3°C, recorded by the Trinidad and Tobago Meteorological Service. Since this is the official temperature monitoring station for T&T’s records, this is our highest maximum temperature, recorded to date at Piarco, for 2020.
Temperatures in cities, such as Port of Spain, tend to be much higher than surrounding locations due to a phenomenon called the Urban Heat Island Effect. There are several causes, but the main instigator for this phenomenon tends to be increased dark surfaces such as roads and pavement in cities, which absorb solar radiation more than surrounding areas.
Where do these temperatures stand compared to our records? The hottest recorded in Trinidad, based on data from the Global Historical Climatology Network (pre-1980) and the Trinidad and Tobago Meteorological Service (1980-2019) stands at 37.8°C recorded on April 20th, 1946 at Wallerfield.
At Piarco International Airport, where the new official records began, the hottest temperature for the year was recorded on September 25th, 1990, at 36.5°C but the hottest April temperature occurred on April 16th, 2016 at a scorching 36.3°C.
Some areas were hotter than others, and you can thank cloud cover for that. While conditions were not favorable for showers, mostly cloudy conditions persisted across areas of Southern and Eastern halves of the island, keeping temperatures lower than parts of Central Trinidad.
The Heat Index
Several persons across the country took to social media to complain about the heat, or more so what outside felt like. This is called the heat index and is a combination of air temperature and relative humidity determining what the air feels like to a person i.e. how hot it actually feels.
The heat index is important because of sweating. Your body sweats in order to cool the skin and maintain a constant, healthy body temperature. This cooling process means that the sweat has to evaporate off the skin to remove heat. However, if the sweat is unable to evaporate, the body isn’t able to regulate temperature.
With high volumes of moisture in the air, also known as high relative humidity, which T&T regularly experience due to its tropical climate, the rate of sweat evaporation decreased. This is because the atmosphere is unable, or has limited potential to hold additional moisture in the atmosphere.
This results in you feeling warmer in humid conditions and cooler in less humid conditions i.e. when relative humidity decreases. As temperature increases, the heat index increases. As relative humidity increases, so does the heat index.
Heat index is generally classified into four categories: caution, extreme caution, dangerous and extremely dangerous. Generally across Trinidad and Tobago, we experience heat indices of caution to extreme caution in times of hot days, with isolated areas experiencing dangerous heat indices such as urban areas.
Today’s High Heat Indices
On Monday 27th April 2020, high heat indices were prevalent across Trinidad and Tobago. Across most of Trinidad and Tobago, heat indices between ranged between 36.0°C and 40.0°C. In urban areas and areas where development is prevalent, the heat index soared above 40.0°C – dangerous levels. At this level, heat cramps and heat exhaustion are likely. Heatstroke becomes probably with strenuous outdoor activity.
High Temperatures To Continue Through April & May
In the short term, a high-pressure system is forecast to continue dominating weather conditions through the next 1-2 weeks.
High pressure systems bring generally dry and stable weather, with sunny skies. This in turn results in higher daytime and afternoon temperatures.
Looking towards the longer term, April and May are two of our warmest months of the local heat season. In the Trinidad and Tobago Meteorological Service’s (TTMS) Rainfall and Temperature Outlook for Trinidad and Tobago, issued on Thursday 2nd April 2020, they expect this pattern to continue in 2020.
In fact, according to the TTMS, the “average day-time maximum and night-time minimum temperatures are very likely to be warmer than average for all of Trinidad and Tobago.” There are also enhanced chances for hot days (34.0°C in Trinidad, 32°C in Tobago) and hot spells.
On through the next 5 days, maximum high temperatures are forecast to be near 32-34°C across Trinidad, and 31-33°C across Tobago. Heat indices are also forecast to be high, near 36-38°C across Trinidad, and 34-35°C across Tobago. Remember, heat indices will be higher in urbanized areas.
Is this a heatwave?
This is also not a hot spell. For a hot spell to be declared in Trinidad and Tobago by the Trinidad and Tobago Meteorological Service, a period of hot temperatures, characterized by maximum temperatures of at least 34.0°C in Trinidad and 32.0°C in Tobago, lasting five or more consecutive days.