Average annual maximum temperature difference from the 1971-2000 average, showing above-average temperatures over the last 120 years. PHOTO COURTESY Professor Ed Hawkins

It is no doubt T&T feels hotter, but how hot is it getting? The Intergovernmental Panel for Climate Change (IPCC) has observed changes in the earth’s climate in every region and across the whole climate system, with temperatures projected to continue rising.

For the Caribbean and other small island developing states, the IPCC’s latest report noted with high confidence, that observed warming in small islands had been attributed to human influence.

In addition, this increase in temperature will continue into the 21st century in all modelled scenarios.

In fact, warming will continue in the 21st century for all global warming levels and future emissions scenarios, further increasing heat extremes and heat stress.

Taking a look back at 2020, it was the eighth warmest year on record. According to the T&T Meteorological Service (TTMS), T&T’s maximum surface temperatures have become warmer and warmed at a rate of 0.24°C per decade, since 1946.

Looking at the data, disaggregated by decade, the last two decades have been the warmest on record, spanning 2001-2010 and 2011-2020 with the mean maximum temperatures of 32.2°C. Since 1981 each decade has been warmer than the 20th century average of 31.1°C.

When looking at excessive heat nationwide, according to chief climatologist at the TTMS Kenneth Kerr, T&T has been recording unusually hot days in the last several decades, with 2011-2020 having the record highest of 415 days where the maximum recorded temperature was at or above 34°C. In this new climate, unusually hot nights have also become more common.

Periods of excessive heat can increase heat stress for persons with heat-sensitive ailments, amplify existing health conditions in vulnerable persons and worsen chronic health conditions in others.

Hot temperatures are only one part of the sweltering conditions outside. What it feels like, or the heat index can be significantly higher. The heat index considers the recorded temperature, winds, and humidity to calculate what outside actually feels like. That figure can be as high as 50°C in urbanised areas like Port-of-Spain, and these temperatures have become more common in recent history.

Generally, cities, urban and developed areas have the highest chance for warmer than average temperatures, and experience the most intense heat on hot days and heat events. These levels of high temperatures can be hazardous to people who may be particularly vulnerable to hot conditions, such as older or frail persons, people with long-term or severe illnesses, young children, and disabled adults who need help responding to the heat.

Warmer than usual temperatures on hot and very hot days can lead to warmer than usual water temperatures, which can cause heat stress such as wilting in aquaponic crops and fisheries. Water temperatures much warmer than 30°C can affect warm-water fish such as tilapia. Further agricultural impacts are possible as hot days and spells can cause heat stress in livestock and wilt, in newly transplanted and younger crops. Based on data from the Global Historical Climatology Network (pre-1980) and the TTMS (1991-2020), the hottest recorded temperature in Trinidad stands at 37.8 C, recorded on April 20, 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. Year-to-date, the highest maximum high temperatures have come in at 34.6°C at Piarco, Trinidad, and 33.9°C at Crown Point, Tobago.