Heat in Northern Hidalgo County, Texas

At South Texas International Airport 11 miles north of Edinburg and on the line between north and south Hidalgo County, peak heat index ranged from 112F to 117F between around 125 and 615 PM CDT, peaking qt 117F between 315 and 415 PM. The Remote Automated Observing Station at Linn-San Manuel recorded max heat indices between 114-120F degrees for 5 hours, between 12:46-5:46 PM CDT on May 24, 2024.

Though heat indices reached Excessive Heat Warning criteria (116 or higher for two or more hours) at Linn/San Manuel with values between 118-120F for 3 hours, from 2:46-5:46 PM CDT, the site has a known high bias and proxy values were more likely close to 116F or 117F for about an hour.

A strong upper-level subtropical ridge/heat dome centered over central and southern Mexico strengthened and shifted northward towards the Rio Grande Valley and Deep South Texas ranchlands the week prior to Memorial Day. The strong ridge aided lower level temperatures at around five thousand feet to soar to between 78 and 86F, which translated to surface temperatures rising into the upper 90s to mid 100s on most days between May 21-25. With dewpoint temperatures well into the 70s to around 80, apparent temperatures (feels like temperatures) ranged anywhere between 111-116F across parts of Deep South Texas and the Rio Grande Valley with a few locales reaching higher than this. The hottest apparent temperatures were located along and east of IH-69C from Hidalgo and Brooks County to Cameron, Willacy, and Kenedy County - but all of Deep South Texas observed at least dangerous heat levels by local definition (111F or higher for at least two hours) on most days.

Actual temperatures during the period were even hotter than the peak of the summer heat (late July through mid August) for most areas. The month would shatter all-time temperature records by 1 to more than 3 degrees.