Unrelenting heat and humidity continued to bring heat advisory criteria (111 or higher for 2 hours or more in a single day) to the Rio Grande Valley, and north to Kenedy County ranch country.

Heat in CAMERON, TEXAS
From 13-JUL-23 11:53:00 to 13-JUL-23 15:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Harlingen-Valley International Airport ASOS reported a heat index of 111 by 2:52 PM CDT, with 111 or higher values persisting until approximately 3:52 PM CDT on July 13th. The Brownsville-South Padre International ASOS reported a heat index of 111 by 12:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT.

Heat in COASTAL CAMERON, TEXAS
From 13-JUL-23 12:53:00 to 13-JUL-23 15:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS reported a heat index of 111 by 1:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on July 13th.

Heat in SOUTHERN HIDALGO COUNTY, TEXAS
From 13-JUL-23 13:15:00 to 13-JUL-23 15:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 111 degrees between 2:53PM CDT and 4:53PM CDT the afternoon of July 13th. The South Texas International Airport AWOS station (KEBG) recorded heat indices reaching or exceeding 111 degrees between 2:15PM CDT and 3:55PM CDT the afternoon of July 13th.

Heat in INLAND KENEDY COUNTY, TEXAS
From 13-JUL-23 15:55:00 to 13-JUL-23 17:05:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Texas Water Development Board Mesonet site in Sarita (TW100) in northern Kenedy County recorded heat indices reaching or exceeding 111 degrees between 4:55PM CDT and 6:05PM CDT the afternoon of July 13th.

Heat in WILLACY, TEXAS
From 13-JUL-23 12:53:00 to 13-JUL-23 15:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

By proxy with nearby ASOS, AWOS, and Texas Water Development Board Mesonet sites, it is realistic to interpolate heat index values between 111 and 115 degrees across inland Willacy County during the afternoon of July 13th. Slightly lower values are common here compared with locations in Kenedy and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.

Heat in STARR, TEXAS
From 13-JUL-23 14:11:00 to 13-JUL-23 17:11:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

The Falcon Lake RAWS location, 28 miles northwest of Roma, reported several hours of heat index between 111 and 114 degrees. The Texas Water Development Board mesonet site at Rancho Los Comitas in far northern Starr County reported peak heat index between 108 and 111 during the same period.  By proxy, it is assumed that populated Starr County locations along the Rio Grande fell somewhere in between for several hours, ranging from 111 to 113.

Heat in STARR, TEXAS
From 14-JUL-23 12:11:00 to 14-JUL-23 17:11:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

The Falcon Lake RAWS location, 28 miles northwest of Roma, reported several hours of heat index between 111 and 114 degrees. The Texas Water Development Board mesonet site at Rancho Los Comitas in far northern Starr County reported peak heat index between 107 and 110 during the same period.  By proxy, it is assumed that populated Starr County locations along the Rio Grande fell somewhere in between for several hours, ranging from 111 to 113.

Heat in SOUTHERN HIDALGO COUNTY, TEXAS
From 14-JUL-23 13:53:00 to 14-JUL-23 14:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The McAllen-Miller International Airport ASOS station (KMFE) recorded heat indices reaching or exceeding 111 degrees between 2:53PM CDT and 3:53PM CDT the afternoon of July 14th.

Heat in NORTHERN HIDALGO COUNTY, TEXAS
From 13-JUL-23 13:15:00 to 13-JUL-23 15:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

It is reasonable to infer that Northern Hidalgo County reached Heat criteria due to readings at the McAllen-Miller International Airport and Edinburg International Airport, both of which reached criteria on July 13th.

Heat in COASTAL WILLACY, TEXAS
From 13-JUL-23 12:53:00 to 13-JUL-23 15:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS reported a heat index of 111 by 1:53 PM CDT, with 111 or higher values persisting until approximately 4:53 PM CDT on July 13th. The Mesowest location a bit farther north, closer to the Willacy line, recorded similar values generally between 122 PM and 422 PM. By proxy with sites farther north, including inland Kenedy, it is assumed that heat index reached 111 for a few hours in coastal Willacy.