The National Weather Service (NWS) in San Juan reports that Puerto Rico will remain under dry, hot conditions in the coming days due to a combination of Saharan dust and a drier air mass dominating the region. A high-pressure system over the central Atlantic is driving east-to-southeast winds, favoring stable conditions and limiting widespread rain, while a low-pressure system in the upper atmosphere over the western Atlantic continues bringing high clouds without significant changes to the dry pattern. Low-level atmospheric temperatures are well above normal for this time of year, partly due to warmer overnight lows caused by the Saharan dust.
The NWS has issued a Heat Advisory in effect from 10:00 a.m. to 5:00 p.m. for all coastal and urban zones of Puerto Rico and the U.S. Virgin Islands, with heat indices expected between 108 and 111 degrees Fahrenheit, raising the risk of heat stress and heat-related illness, especially among vulnerable populations. Isolated showers or storms remain possible in western Puerto Rico in the afternoon due to daytime heating.
The NWS said dry conditions will persist Wednesday, with relative humidity potentially dropping to 20%-30%, unusually low for this time of year, while high clouds and Saharan haze keep overnight temperatures elevated and heat risk high in urban and coastal areas.