Heat index rises above 112 Fahrenheit on Tuesday

The temperature in San Juan early Tuesday afternoon stood at 90 degrees Fahrenheit, as a heat index of 112 degrees was estimated for the day.

By The Star Staff

The National Weather Service (NWS) on Tuesday issued an excessive heat advisory and heat warning for several towns in Puerto Rico that was in effect from 10 a.m. until 5 p.m., with heat index values above 112 degrees Fahrenheit estimated.

The excessive heat advisory included the Bayamón, Carolina, Cataño, Guaynabo, San Juan, Toa Alta, Toa Baja, Trujillo Alto, Ceiba, Canóvanas, Fajardo, Humacao, Loíza, Luquillo, Naguabo, Río Grande, Aguas Buenas, Caguas, Cayey, Cidra, Comerío, Gurabo, Juncos, Las Piedras, San Lorenzo, Arecibo, Barceloneta, Dorado, Florida, Manatí, Vega Alta, Vega Baja, Aguadilla, Camuy, Hatillo, Isabela, Quebradillas, Aguada, Añasco, Hormigueros, Mayagüez, Moca, Rincón, and San Germán.

The temperature in San Juan at 1:30 p.m. Tuesday stood at 90 degrees.

According to the NWS, a heat advisory is issued within 12 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for a heat advisory is when the maximum heat index temperature is expected to be 100° or higher for at least two days, and night time air temperatures will not drop below 75°; however, those criteria vary across the country, especially for areas that are not used to dangerous heat conditions. Taking precautions to avoid heat illness is strongly advised. Failure to take precautions may lead to serious illness or even death.

Another heat warning includes the towns of Arroyo, Guayama, Maunabo, Patillas, Salinas, Yabucoa, Guayanilla, Juana Díaz, Yauco, Peñuelas, Ponce, Santa Isabel, Cabo Rojo, Guánica, Lajas, Culebra and Vieques.

Heat index values of 108 to 111 degrees Fahrenheit were estimated in those towns.

Heat watches are issued when conditions are favorable for an excessive heat event in the next 24 to 72 hours. A heat watch is used when the risk of a heat wave has increased but its occurrence and timing is still uncertain.

According to the NWS, the island will cool off somewhat today with a heat index value as high as 103 and isolated showers before 9 a.m,, then isolated showers after noon, with widespread haze. Mostly sunny conditions are forecast, with a high near 90 degrees, and east winds from 11 to 16 mph. The chance of precipitation is 20%.

On Thursday, scattered showers are forecast, mainly before noon, with widespread haze after noon; mostly sunny are again expected, with a high near 89 and east winds at 13 to 16 mph, with gusts as high as 21 mph. The chance of precipitation will be 30%.