The recent high temperatures and excessive heat indices experienced across the USVI and Puerto Rico have created dangerous conditions for the health of individuals across the islands. The extraordinarily high heat index levels resulted in multiple weather alerts, including a “Heat Advisory” for portions of the USVI. The hot temperatures even made national headlines, including weather alerts on Fox Weather and NBC News.
With the hot weather occurring relatively early in the season, residents and visitors in the USVI may be wondering if this type of heat is expected to be typical according to historical records, as well as questioning whether or not the high temperatures are expected to continue, especially if related to climate change.
The Source addressed some of these questions with Ernesto Morales, a Warning Coordination Meteorologist at the National Weather Service in San Juan, Puerto Rico. Morales noted that while high heat can occur across the big island of Puerto Rico, sweltering temperatures are relatively uncommon on the small islands of the USVI.
Hot Temperatures and a High Heat Index
“We’re going to focus on the Virgin Islands,” said Morales. “The good thing about the Virgin Islands is that they’re smaller islands than Puerto Rico. So, you have much less effects on temperature due to land [size]. When we get the southerly winds, the air gets warmer. And the areas where you’re going to see higher [temperatures] are going to be in the northern half of Puerto Rico. But it is very rare to have these types of temperatures in the Virgin Islands,” he added.
Regarding the current weather pattern, Morales points out that southerly winds, combined with warm ocean water temperatures, can aid in creating hot weather across the region.
“We’ve had straight, southerly winds. This will help to create a high temperature across the islands. Plus, the water surrounding the islands is around 84 degrees Fahrenheit. This will help maintain the atmosphere, causing the air to be warmer. And what is affecting us is the combination of hot weather and humidity,” Morales explained.
Typically, precipitation is expected when the air is warm and humidity is high. However, recently a lack of significant rainfall is helping to allow the heat to soar to high levels.
“Right now, the environment is so stable and dry in the mid to upper levels that it’s not helping the showers develop. And showers are really important, because it’s a cooling mechanism that we have over the islands,” Morales noted.
The scorching heat can result in a dangerously high “heat index,” Morales warned.
Staying Safe During Hot Weather
Even when the actual temperature is very high, the “heat index” is often higher. “The heat index, also known as the apparent temperature, is what the temperature feels like to the human body when relative humidity is combined with the air temperature,” according to a definition from the National Weather Service.
When the humidity in the air is high, the result can be heat exhaustion or heat stroke.
With the heat reaching dangerously high levels, staying hydrated and as cool as possible is extremely important – for humans and pets as well. Morales offers the following advice regarding staying safe in the heat.
“What we recommend to the public is to stay in the shade. Drink a lot of water. And if you need to be working or doing something outside, try to complete activities outside of the peak periods of heat between 10 a.m. and 5 p.m. [And if you have to be outside in the heat,] do not expose yourself for more than 15 minutes. Everybody should know their limitations,” Morales warned.
A Possible Connection to Climate Change?
A look at historical temperature data on the National Oceanic and Atmospheric Administration website for the U.S. Virgin Islands indicates that the highest temperature ever recorded was 99 degrees Fahrenheit. This temperature was recorded at Charlotte Amalie on St. Thomas on June 23, 1996, and this was the last time the territory officially reached that heat level.
Morales acknowledged the effects of climate change overall, and he noted that the extended period of heat across the region potentially appears to be a relatively infrequent event. However, he stressed that additional analysis and studies would need to be completed in order to make a distinct connection between the current hot temperatures and a changing climate.
“We need to sit down and look at the numbers and see if there are trends and correlations with climate change. We cannot directly say this is climate change. But we know that climate change is real,” Morales explained. “We know that the effects of climate change over the Caribbean area are higher temperatures, sea level rises, and more extreme [weather] events. All of this describes what we’re having right now. But before we make that correlation, we have to do some research to see if there’s any connection between climate change and this [current] period of high temperatures.”
More information on weather conditions is available on the National Weather Service website. Additionally, the weather forecast and weather alerts will be updated on the Source Weather Page. USVI residents and visitors may also sign up for emergency alerts from the Virgin Islands Territorial Emergency Management Agency.
