A dome of strong atmospheric high pressure - known locally as La Canicula, provided a prolonged period of hot to very hot temperatures combined with high humidity to lead to excessively heat index values in mid-June. High temperatures were in the upper 90s to middle 100s June 13th through June 17th. Heat indices ranged from 116 to 125-degrees every afternoon across much of the area, from Hidalgo and Brooks County eastward.  Heat indices ranged from 111 to 115 in these counties and farther west (Jim Hogg, Starr, and Zapata) on occasion through the period; these are considered Heat Advisory days with a slightly lower threshold for life-threatening conditions, but still dangerous.
The heat dome would continue through the end of June, with advisory or warning level heat index for all or part of the Rio Grande Valley and Deep South Texas through the period, and into July.
Local hospitals noted an increase in heat-related emergency room visits during this period when compared with the same period a year earlier, which was also hot but not at the level of 2023.  Percentage increases ranged from 11 to 18 percent more visits during the month of June. Detailed information on heat-related illnesses (actual numbers of injuries or fatalities) was not known as of the end of August.

Excessive Heat in SOUTHERN HIDALGO COUNTY, TEXAS
From 16-JUN-23 11:53:00 to 16-JUN-23 16:53:00 (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 116 degrees between 12:53PM CDT and 5:53PM CDT the afternoon of June 16th. The highest heat index was recorded at 5:53PM CDT of 121 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 120 degrees at 3:55PM CDT.

Heat in STARR, TEXAS
From 14-JUN-23 13:30:00 to 14-JUN-23 18:20:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County) recorded heat index values of 111 to 115 generally between 230 PM and 6 PM CDT. The RAWS site at Falcon Lake, which runs hotter than most locations but is a proxy for locations along the Rio Grande in Starr, had actual temperatures of 110 and heat index between 111 and 119 between 12:11 and 7:11 PM CDT. The time provided is a blend of the two observations, and Starr County overall was likely between 111 and 115 during this window.

Heat in COASTAL WILLACY, TEXAS
From 15-JUN-23 12:30:00 to 15-JUN-23 18:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS near Bayview reported around six hours of heat index at or above 111 degrees during the afternoon of June 15th, peaking at 114 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.  Interpolation between these sites and the slightly more inland site near Sarita (Kenedy) is a good proxy for Coastal Willacy.

Excessive Heat in SOUTHERN HIDALGO COUNTY, TEXAS
From 17-JUN-23 11:53:00 to 17-JUN-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 116 degrees between 12:53PM CDT and 4:53PM CDT the afternoon of June 16th. The highest heat index was recorded at 1:53PM CDT of 117 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 119 degrees at 2:35PM CDT.

Excessive Heat in NORTHERN HIDALGO COUNTY, TEXAS
From 14-JUN-23 12:55:00 to 14-JUN-23 15:55:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

It is reasonable to infer that Northern Hidalgo County reached Excessive Heat criteria due to readings at the McAllen-Miller International Airport and Edinburg International Airport, both of which reached criteria on June 14th.

Heat in JIM HOGG, TEXAS
From 14-JUN-23 15:55:00 to 14-JUN-23 18:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Though Jim Hogg County AWOS reported no hours of heat index reaching or exceeding  111 degrees and 113 during the afternoon of June 14, 2023, the Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County near the Jim Hogg County line) recorded values of 111 to 113 between 5 PM and 730 PM CDT, after humidity recovered during the late afternoon.

Heat in COASTAL WILLACY, TEXAS
From 16-JUN-23 10:30:00 to 16-JUN-23 16:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS near Bayview reported around six hours of heat index at or above 111 degrees during the afternoon of June 16th, peaking at 117 at 3:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.  Interpolation between these sites and the slightly more inland site near Sarita (Kenedy) is a good proxy for Coastal Willacy.

Excessive Heat in SOUTHERN HIDALGO COUNTY, TEXAS
From 13-JUN-23 12:53:00 to 13-JUN-23 17:53:00 (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 116 degrees between 1:53PM CDT and 6:53PM CDT the afternoon of June 13th. The highest heat index was recorded at 4:53PM CDT of 121 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 121 degrees at 5:55PM CDT.

Heat in WILLACY, TEXAS
From 14-JUN-23 13:30:00 to 14-JUN-23 15:30:00 (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 113 degrees across inland Willacy County during the afternoon of June 14th.  Slightly lower values are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.

Heat in COASTAL WILLACY, TEXAS
From 17-JUN-23 10:30:00 to 17-JUN-23 15:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS near Bayview reported around five hours of heat index between 111 and 115 degrees during the afternoon of June 17th, peaking at 117 at 12:49 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.  Interpolation between these sites and the slightly more inland site near Sarita (Kenedy) is a good proxy for Coastal Willacy.

Excessive Heat in NORTHERN HIDALGO COUNTY, TEXAS
From 15-JUN-23 13:15:00 to 15-JUN-23 16:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

It is reasonable to infer that Northern Hidalgo County reached Excessive Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on June 15th.

Excessive Heat in NORTHERN HIDALGO COUNTY, TEXAS
From 16-JUN-23 11:53:00 to 16-JUN-23 16:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

It is reasonable to infer that Northern Hidalgo County reached Excessive Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on June 16th.

Heat in COASTAL CAMERON, TEXAS
From 15-JUN-23 12:30:00 to 15-JUN-23 18:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS near Bayview reported around four hours of heat index at or above 111 degrees during the afternoon of June 15th, peaking at 114 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.

Heat in COASTAL KENEDY, TEXAS
From 15-JUN-23 12:00:00 to 15-JUN-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Cameron County Airport ASOS near Bayview reported around six hours of heat index at or above 111 degrees during the afternoon of June 15th, peaking at 114 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.  Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100) is a good proxy for Coastal Kenedy, with a slightly earlier start time and later end time.

Excessive Heat in NORTHERN HIDALGO COUNTY, TEXAS
From 17-JUN-23 11:53:00 to 17-JUN-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 Excessive Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on June 17th.

Excessive Heat in CAMERON, TEXAS
From 13-JUN-23 14:52:00 to 13-JUN-23 14:52:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Valley International Airport ASOS station in Harlingen (KHRL) recorded heat indices reaching or exceeding 116 degrees at 3:52PM CDT the afternoon of June 13th. The highest heat index recorded was at 3:52PM CDT of 118 degrees.

Heat in COASTAL WILLACY, TEXAS
From 13-JUN-23 14:30:00 to 13-JUN-23 17:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County ASOS reported heat index around 112 degrees from approximately 1:53 PM through 3:53 PM on the 13th. Interpolating between observations along the bayside of Cameron County with those of inland Kenedy and Kleberg County to the north suggests similar values occurred in Coastal Willacy at the same time as well - prior to the spike and just after the period of these values gives a better range of 111 degrees or higher.

Heat in COASTAL KENEDY, TEXAS
From 16-JUN-23 11:45:00 to 16-JUN-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Cameron County Airport ASOS near Bayview reported around six hours of heat index at or above 111 degrees during the afternoon of June 16th, peaking at 117 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.
Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100), which had slightly lower heat index values (generally, 111 to 115) is a good proxy for Coastal Kenedy. This site peaked at around 116 degrees at 405 PM CDT.

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

The Valley International Airport ASOS station in Harlingen (KHRL) recorded heat indices reaching or exceeding 116 degrees at 2:52PM CDT the afternoon of June 15th. The highest heat index recorded was at 2:52PM CDT of 116 degrees. The Brownsville-South Padre International Airport ASOS station (KBRO) recorded heat indices reaching or exceeding 116 degrees between 1:53PM CDT and 4:53PM CDT the afternoon of June 15th. The highest heat index recorded was at 3:15PM CDT of 118 degrees.

Heat in COASTAL KENEDY, TEXAS
From 13-JUN-23 13:30:00 to 13-JUN-23 17:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Cameron County ASOS reported heat index around 112 degrees from approximately 1:53 PM through 3:53 PM on the 13th. Interpolating between observations along the bayside of Cameron County with those of inland Kenedy (TW100) and Kleberg County to the north suggests similar values occurred in Coastal Kenedy at a bit later time, associated with the arrival of the sea breeze gives a better range of 111 degrees or higher.

Heat in COASTAL KENEDY, TEXAS
From 17-JUN-23 11:45:00 to 17-JUN-23 18:45:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Cameron County Airport ASOS near Bayview reported around seven hours of heat index at or above 111 degrees during the afternoon of June 16th, peaking at 117 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.
Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100), which had similar heat index values (generally, 111 to 115, briefly peaking at 118 degrees around 6 PM CDT) is a good proxy for Coastal Kenedy.

Excessive Heat in CAMERON, TEXAS
From 16-JUN-23 11:52:00 to 16-JUN-23 14:52:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Valley International Airport ASOS station in Harlingen (KHRL) recorded heat indices reaching or exceeding 116 degrees between 12:52PM CDT and 3:52PM CDT the afternoon of June 16th. The highest heat index recorded was at 12:52PM CDT of 118 degrees. The Brownsville-South Padre International Airport ASOS station (KBRO) recorded heat indices reaching or exceeding 116 degrees at 12:53PM CDT the afternoon of June 16th. The highest heat index recorded was at 12:53PM CDT of 117 degrees.

Heat in COASTAL WILLACY, TEXAS
From 14-JUN-23 12:30:00 to 14-JUN-23 16:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS near Bayview reported around four hours of heat index at or above 111 degrees during the afternoon of June 14th, peaking at 115 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 113 roughly during the same time period.  Interpolation between these sites and the slightly more inland site near Sarita (Kenedy) is a good proxy for Coastal Willacy.

Heat in WILLACY, TEXAS
From 16-JUN-23 11:40:00 to 16-JUN-23 16:45:00 (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 114 degrees across inland Willacy County during the afternoon of June 16th.  Slightly lower values (below excessive heat criteria, or 116F) are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.

Excessive Heat in CAMERON, TEXAS
From 17-JUN-23 11:53:00 to 17-JUN-23 13:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Brownsville-South Padre International Airport ASOS station (KBRO) recorded heat indices reaching or exceeding 116 degrees between 12:53PM CDT and 2:53PM CDT the afternoon of June 17th. The highest heat index recorded was at 12:53PM CDT of 117 degrees.

Excessive Heat in INLAND KENEDY COUNTY, TEXAS
From 14-JUN-23 16:30:00 to 14-JUN-23 17:30:00 (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 116 degrees between 5:30PM CDT and 6:30PM CDT the afternoon of June 14th. The highest heat index was recorded at 5:30PM CDT of 119 degrees.

Heat in COASTAL KENEDY, TEXAS
From 14-JUN-23 14:30:00 to 14-JUN-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Cameron County Airport ASOS near Bayview reported around four hours of heat index at or above 111 degrees during the afternoon of June 14th, peaking at 115 at 2:53 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 113 roughly during the same time period.  Interpolation between these sites and the slightly more inland site near Sarita (Kenedy - Texas Water Development Board Mesonet station 100) is a good proxy for Coastal Kenedy, with a slightly later start and end time.

Heat in WILLACY, TEXAS
From 17-JUN-23 12:00:00 to 17-JUN-23 16:00:00 (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 114 degrees across inland Willacy County during the afternoon of June 17th.  Slightly lower values (below excessive heat criteria, or 116F) are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.

Excessive Heat in BROOKS, TEXAS
From 13-JUN-23 15:55:00 to 13-JUN-23 18:15:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Brooks County Airport (KBKS) recorded heat indices reaching or exceeding 116 degrees between 4:15PM CDT and 7:15PM CDT the afternoon of June 13th. The highest heat index was recorded at 6:35PM CDT of 123 degrees.

Excessive Heat in INLAND KENEDY COUNTY, TEXAS
From 15-JUN-23 15:20:00 to 15-JUN-23 17:10:00 (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 116 degrees between 4:20PM CDT and 6:10PM CDT the afternoon of June 15th. The highest heat index was recorded at 5:10PM CDT of 119 degrees.

Excessive Heat in INLAND KENEDY COUNTY, TEXAS
From 16-JUN-23 13:40:00 to 16-JUN-23 14:20:00 (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 116 degrees between 2:40PM CDT and 3:20PM CDT the afternoon of June 16th. The highest heat index was recorded at 2:40PM CDT of 117 degrees.

Heat in JIM HOGG, TEXAS
From 15-JUN-23 14:00:00 to 15-JUN-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Though Jim Hogg County AWOS reported no hours of heat index reaching or exceeding  111 degrees during the afternoon of June 15, 2023, the Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County near the Jim Hogg County line) recorded values of 111 to 115 between 3 PM and 7 PM CDT, after humidity recovered during the late afternoon. With Jim Hogg County AWOS falling just shy of 111, proxy observations suggest the majority of the county reached local advisory-level criteria.

Heat in JIM HOGG, TEXAS
From 16-JUN-23 13:00:00 to 16-JUN-23 19:15:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Jim Hogg County AWOS reported approximately 6 hours  of heat index reaching or exceeding  111 degrees during the afternoon of June 16, 2023, peaking at 115 degrees at 735 PM CDT.  The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County near the Jim Hogg County line) recorded values of 111 to 115 between 2 PM and 7 PM CDT, after humidity remained steady between 35 and 40 percent covered during the late afternoon.

Excessive Heat in BROOKS, TEXAS
From 15-JUN-23 16:15:00 to 15-JUN-23 17:35:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Brooks County Airport (KBKS) recorded heat indices reaching or exceeding 116 degrees between 5:15PM CDT and 6:35PM CDT the afternoon of June 15th. The highest was recorded at 5:15PM CDT of 117 degrees.

Excessive Heat in BROOKS, TEXAS
From 16-JUN-23 14:35:00 to 16-JUN-23 17:55:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Brooks County Airport (KBKS) recorded heat indices reaching or exceeding 116 degrees between 3:35PM CDT and 6:55PM CDT the afternoon of June 16th. The highest was recorded at 4:35PM CDT of 127 degrees.

Excessive Heat in INLAND KENEDY COUNTY, TEXAS
From 17-JUN-23 15:50:00 to 17-JUN-23 17:50:00 (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 116 degrees between 4:50PM CDT and 6:50PM CDT the afternoon of June 17th. The highest heat index was recorded at 6:00PM CDT of 121 degrees.

Heat in ZAPATA, TEXAS
From 15-JUN-23 15:30:00 to 15-JUN-23 17:45:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Zapata County Airport AWOS reported a heat index of 111 by around 4 PM CDT, with 111 or higher values persisting until approximately 545 PM CDT. Proxy observations to other sites along the Rio Grande in Zapata County suggest duration could have reached 3 to 4 hours in a few locations.

Heat in JIM HOGG, TEXAS
From 17-JUN-23 12:45:00 to 17-JUN-23 18:05:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Jim Hogg County AWOS reported approximately 3 hours  of heat index reaching or exceeding  111 degrees during the afternoon of June 16, 2023, peaking just below 114  degrees at 535 PM CDT.  The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County near the Jim Hogg County line) recorded values of 111 to 114 between 145 PM and 705 PM CDT, as humidity held firm between 39 and 43 percent  during the late afternoon.

Excessive Heat in BROOKS, TEXAS
From 17-JUN-23 10:35:00 to 17-JUN-23 17:55:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Brooks County Airport (KBKS) recorded heat indices reaching or exceeding 116 degrees between 11:35AM CDT and 6:55PM CDT the afternoon of June 17th. The highest was recorded at 4:55PM CDT of 119 degrees.

Excessive Heat in NORTHERN HIDALGO COUNTY, TEXAS
From 13-JUN-23 12:53:00 to 13-JUN-23 17:53:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

It is reasonable to infer that Northern Hidalgo County reached Excessive Heat criteria due to readings at the McAllen-Miller International Airport, South Texas International Airport, and Brooks County Airport, all of which reached criteria on June 13th.

Heat in WILLACY, TEXAS
From 13-JUN-23 13:30:00 to 13-JUN-23 17:30:00 (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 June 13th.  Slightly lower values are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.

Heat in STARR, TEXAS
From 15-JUN-23 14:00:00 to 15-JUN-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County) recorded heat index values of 111 to 115 generally between 230 PM and 6 PM CDT. The RAWS site at Falcon Lake, which runs hotter than most locations but is a proxy for locations along the Rio Grande in Starr, had actual temperatures of 110 and heat index between 111 and 119 between 12:11 and 6:11 PM CDT. The time provided is a blend of the two observations, and Starr County overall was likely between 111 and 115 during this window.

Heat in ZAPATA, TEXAS
From 16-JUN-23 14:00:00 to 16-JUN-23 19:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Zapata County Airport AWOS reported a heat index of 111 by around 3 PM CDT, with 111 or higher values persisting until approximately 8 PM CDT. Peak value was just below 113 at 415 PM CDT. Proxy observations to other sites along the Rio Grande in Zapata County suggest duration could have reached 5 to 7 hours in a few locations during the same time.

Excessive Heat in SOUTHERN HIDALGO COUNTY, TEXAS
From 14-JUN-23 12:55:00 to 14-JUN-23 15:55:00 (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 116 degrees between 1:55PM CDT and 4:55PM CDT the afternoon of June 14th. The highest heat index was recorded at 3:53PM CDT of 118 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 118 degrees at 4:15PM CDT.

Heat in COASTAL CAMERON, TEXAS
From 13-JUN-23 13:30:00 to 13-JUN-23 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County ASOS reported heat index around 112 degrees from approximately 1:53 PM through 3:53 PM on the 13th. Interpolating between observations prior to the spike and just after the period of these values gives a better range of 111 degrees or higher.

Heat in ZAPATA, TEXAS
From 14-JUN-23 15:35:00 to 14-JUN-23 16:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Zapata County Airport AWOS reported a heat index of 111 by 4:35 PM CDT, with 111 or higher values persisting until approximately 530 PM CDT. Proxy observations to other sites along the Rio Grande in Zapata County suggest duration could have reached 3 hours in a few locations.

Heat in WILLACY, TEXAS
From 15-JUN-23 12:40:00 to 15-JUN-23 17:40:00 (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 114 degrees across inland Willacy County during the afternoon of June 15th.  Slightly lower values (below excessive heat criteria, or 116F) are common here compared with locations in Kenedy/Brooks and Cameron, due to the populated areas being in a zone of slightly lower, but still dangerous, high temperatures.

Heat in ZAPATA, TEXAS
From 17-JUN-23 13:15:00 to 17-JUN-23 17:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Zapata County Airport AWOS reported a heat index of 111 by around 215 PM CDT, with 111 or higher values persisting until approximately 630 PM CDT. Peak value was just below 114 at 235 PM CDT. Proxy observations to other sites along the Rio Grande in Zapata County suggest duration could have reached 4 to 6 hours in a few locations.

Excessive Heat in SOUTHERN HIDALGO COUNTY, TEXAS
From 15-JUN-23 13:15:00 to 15-JUN-23 16:53:00 (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 116 degrees between 2:15PM CDT and 5:53PM CDT the afternoon of June 15th. The highest heat index was recorded at 5:53PM CDT of 119 degrees. The South Texas International Airport AWOS station (KEBG) recorded a max heat index of 120 degrees at 3:35PM CDT.

Heat in JIM HOGG, TEXAS
From 13-JUN-23 14:15:00 to 13-JUN-23 17:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Jim Hogg County AWOS reported several hours of heat index between 111 and 113 during the afternoon of June 13, 2023.  Dangerous heat began at around 315 PM CDT and continued through 630 PM CDT.  Peak values of 113 occurred at 415 PM CDT.  The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County) recorded values of 111 to 112 during the same time frame.

Heat in COASTAL CAMERON, TEXAS
From 17-JUN-23 10:30:00 to 17-JUN-23 15:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS near Bayview reported around five hours of heat index between 111 and 115 degrees during the late morning and afternoon of June 17th, peaking at 117 at 12:49 PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 roughly during the same time period.

Heat in STARR, TEXAS
From 13-JUN-23 13:30:00 to 13-JUN-23 18:20:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The Texas Mesonet site at Rancho Los Comitas (extreme northern Starr County) recorded heat index values of 111 to 115 generally between 230 PM and 6 PM CDT. The RAWS site at Falcon Lake, which runs hotter than most locations but is a proxy for locations along the Rio Grande in Starr, had actual temperatures of 110 and heat index between 111 and 119 between 12:11 and 7:11 PM CDT. The time provided is a blend of the two observations, and Starr County overall was likely between 111 and 115 during this window.

Heat in COASTAL CAMERON, TEXAS
From 16-JUN-23 10:30:00 to 16-JUN-23 16:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport ASOS near Bayview reported around six hours of heat index between 111 and 115 degrees during the late morning and afternoon of June 17th, peaking at 117 at 3:53  PM CDT. Laguna Atascosa National Wildlife Refuge reported heat index between 111 and 115 degrees roughly during the same time period.

Heat in COASTAL CAMERON, TEXAS
From 14-JUN-23 11:30:00 to 14-JUN-23 15:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County ASOS reported heat index between 111 and 115 degrees from approximately 12:30 PM through 4:30 PM on the 13th. Interpolating between observations prior to the spike and just after the period of these values gives a better range of 111 degrees or higher.  Similar values and times were reported at Laguna Atascosa National Wildlife Refuge.