Heat in Southern Hidalgo County, Texas

The third day of a trifecta of dangerous heat saw the Automated Surface Observing System (ASOS) at McAllen/Miller Int'l. Airport record a peak heat index value 114.65F during the mid afternoon, with four hours of values between 111 and 113F overall. Weslaco/Mid Valley Airport recorded a peak of 111F, with several observations just below this. By proxy, it is assume that much of Southern Hidalgo had values in advisory levels (111 to 115).

As developing Tropical Storm Arthur moved along the middle Texas coast (June 17) and as a degenerated low pressure system along the Louisiana Coast (June 18), very hot air descended on the southern tip of Texas, with record extreme heat index, or feels-like, temperatures for the entire region on the 18th. The high heat index values held on into June 19th, before unsettled weather brought slightly lower temperatures and pockets of rain by the 20th, which ended the short but brutal window of extreme heat.