Excessive Heat in Willacy, Texas

Harlingen Valley International Airport (KHRL) recorded max heat indices between 110-120F for 5 hours, from 11:52 AM-4:52 PM CDT on May 28, 2024. Values reached excessive heat criteria (116F or higher) from approximately 1230 until 345 PM. By proxy, it can be inferred that southern Willacy County had excessive heat values for a similar time period. Note that the Texas Mesonet site at AgriScience Center recorded 111F or higher heat index from 1255 until 540 PM, with a shorter window (345 until 410 PM) with peak heat index between 116 and 117.6F.

A slightly stronger sub-tropical ridge/heat dome centered over central and southern Mexico returned northward towards the Rio Grande Valley and Deep South Texas. At five thousand feet above ground, the temperature soared anywhere from 78 to 90 degrees Fahrenheit, which translated into another short-lived but intense heat wave over the region with surface temperatures rising into the upper 90s to mid 100s from May 26-30. The combination of heat and dewpoint temperatures well into the 70s to around 80, heat indices ranged between a sweltering 111F-126F across parts of Deep South Texas and the Rio Grande Valley. The hottest temperatures were once again located from the mid-lower Rio Grande Valley northward along I-69E and I-69C; several hours with values of 116 or higher - considered Excessive Heat - were noted each day in many parts of the region.