Excessive Heat — Southern Hidalgo County, Texas

2024-05-08 · Southern Hidalgo County, Texas

Event narrative

Peak Heat Index reached 116F at McAllen/Miller Airport at around 130 PM CST and continue through around 630 PM CST on May 8th, peaking at 121F at 353 PM CST. Nearby Lower Rio Grande Valley Wildlife Refuge Remote Automated Weather Sensor (RAWS) along the Rio Grande southeast of Pharr recorded more than 123F, but this value is likely a high bias. Still, it was likely that realistic values of 116 to 120 occurred in much of southern Hidalgo County. Dangerous heat index values of 111 began at 1240 PM CST and continued through 710 PM CST.

Wider weather episode

An unseasonably strong sub-tropical ridge/heat dome centered over central and southern Mexico strengthened and shifted northward towards the Rio Grande Valley/Deep South Texas region. Temperatures at around 5,000 feet above the ground soared to 78 to 86 degrees Fahrenheit over the local area. This translated to surface temperatures rising into the upper 90s to mid 100s from May 7-9. Combined with dewpoint temperatures in the 70s to around 80, this produced apparent, or feels-like temperatures, between 111-116F across locations along and east of IH-69C/US 281 from Brooks/Hidalgo County into Cameron, Willacy, and Kenedy County. The hottest temperatures were located from the mid-lower Rio Grande Valley northward along I-69E and I-69C, peaking on May 9th.

Source: NOAA Storm Events Database, event_id 1188859. Narrative written by the NWS forecast office that issued the report.