Morning lows bottomed out near 17.00°C across interior areas of Trinidad, generally remaining in the low twenties to upper teens across both islands. Minimum low temperatures were recorded as of 7:00 AM.
Morning lows across Trinidad have dipped near or below 20°C over the last two days, with a few areas just above 17°C on Wednesday morning as of 7:00 AM. At Piarco, temperatures dipped to 19.1°C.
Parts of interior Trinidad, such as Penal, saw morning low temperatures as low as 17.04°C. Temperatures across Tobago, albeit still cool, have remained above 23°C.
The record low temperature for April at Piarco (where official records at kept and recorded) was 17.8°C.
Low temperatures during this time of year are normal.
As we progress through the week, overnight low temperatures are forecast to remain in the low twenties across both islands, with areas in the upper teens across parts of Trinidad for one more night. However, with increasing low-level moisture on Thursday, temperatures may not return below that 20-degree point.
According to the Trinidad and Tobago Meteorological Service, “This was also followed by a 19.8°C min, recorded on the 31st of March. The minimum temperature is expected to remain fairly low over the next few days, however some changes in the atmosphere would make it unlikely to go below 21°C”
Cool temperatures across Trinidad result of several factors occurring:
- Calm/near calm winds
- Almost no cloud coverage
- Winds originating from the Northeast to the north at some of the lower levels of the atmosphere (over Trinidad)
- Low amounts of low-level moisture (water vapor)
The dew point, which is the atmospheric temperature below which water droplets begin to condense and dew can form, meteorologists can determine both the moisture content of the atmosphere near the surface, as well as an estimate for the minimum temperature.
A lower dew point means that there is less water vapor in the air. Water vapor can absorb and radiate heat back to the surface. Hence, the lower the water vapor content, the more infrared radiation (i.e. long-wave radiation) can escape from the surface of the earth and cause rapid cooling.
Calm winds and no cloud coverage are due to a persistent sub-tropical high-pressure system that continues to dominate the weather during the dry season, causing dry air at mid and upper levels of the atmosphere, inhibiting cloud formation.
Lack of cloud coverage also leads to fairly warm days, where temperatures can reach 30-33°C.
Particularly during El Niño years (we are in ENSO neutral conditions, with similar conditions to La Niña likely later this year), winter storms move further southward across the United States, increasing the likelihood of cold frontal systems moving across the Caribbean and further dipping temperatures. On the rare occasion, a cold front does manage to make it as far south as Trinidad and Tobago, cold conditions would be due to a process called advection, where there is a horizontal mass movement of air.
For vulnerable persons, who might be especially susceptible to cooler temperatures, such as babies or people suffering from arthritis, it may be best to layer up as a way to keep warm at night.