Excessive Heat in Northern Hidalgo County, Texas

Linn-San Manuel (Remote Automated Weather Sensor) recorded heat indices between 116-122F for 6 hours, from 12:46-6:46 PM CDT (1146-546 PM CST) on May 9, 2024. Between the hours of 11:46 AM to 7:46 PM CDT (1046 AM to 656 PM CST) (8 hours), heat indices were at least 111F. The South Texas International Airport (north of Edinburg) recorded heat indices between 117-123F for 4 hours, from 1:55-5:55 PM CDT (1255 to 455 PM CST) on May 9, 2024. Between the hours of 1:55 PM to 7:55 PM CDT (1255 to 655 CST; 6 hours), heat indices were at least 111F.

As of this writing, there were no known fatalities from these near-record heat index values (annual), but hospitalizations increased compared with average in the McAllen/Mission area due to heat-related illnesses.

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.