The unrelenting pattern known as 'La Canicula' (the Dog Days of Summer) produced a final round of excessive heat just after astronomical summer (which ended on September 22) of 2023.  Afternoon heat index values reached or exceeded 111 for several hours in these areas, and ambient temperatures were at or just below 100 degrees during the period.

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

The Cameron County Airport Automated Surface Observing System recorded approximately four hours of apparent temperature of 111 or higher, with values peaking at 115 degrees just before 2 pm.

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

The Cameron County Airport Automated Surface Observing System recorded approximately four hours of apparent temperature of 111 or higher, with values peaking at 115 degrees just before 2 pm. By proxy, similar values can be extrapolated to locations in Coastal Willacy County.

Heat in COASTAL WILLACY, TEXAS
From 24-SEP-23 11:30:00 to 24-SEP-23 15:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport Automated Surface Observing System recorded four hours of  apparent temperature of 111 or higher, with values peaking at just under 116 degrees between noon and 1 PM.  By proxy, it can be inferred through extrapolation that Coastal Willacy County had similar conditions. This was the hottest feeling day of the three-day late-September stretch.

Heat in COASTAL KENEDY, TEXAS
From 24-SEP-23 11:30:00 to 24-SEP-23 16:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport Automated Surface Observing System recorded four hours of  apparent temperature of 111 or higher, with values peaking at just under 116 degrees between noon and 1 PM.  Farther north, the typically high-reading location at Kingsville Naval Air Station recorded heat index values above 111 from 1130 AM until 630 PM (CDT), with a peak value of 119 just before 4 PM. By proxy, it can be inferred through extrapolation that Coastal Kenedy County had lesser conditions than Kingsville, but similar to those in Coastal Cameron/Willacy. This was the hottest feeling day of the three-day late-September stretch.

Heat in COASTAL CAMERON, TEXAS
From 24-SEP-23 11:30:00 to 24-SEP-23 15:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport Automated Surface Observing System recorded four hours of  apparent temperature of 111 or higher, with values peaking at just under 116 degrees between noon and 1 PM.  This was the hottest feeling day of the three-day late-September stretch.

Heat in CAMERON, TEXAS
From 24-SEP-23 10:00:00 to 24-SEP-23 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Brownsville/South Padre Island International Airport Automated Surface Observing System recorded four hours of apparent temperature of 111 or higher, with values peaking at just under 114 degrees between 1 and 2 PM. Harlingen/Valley International Airport only touched 111 degrees at around 3 PM CDT, but proxies to other observations suggest that inland Cameron had several areas with at least 2 hours of 111 degree or higher heat index values. This was the hottest feeling day of the three-day late-September stretch.

Heat in WILLACY, TEXAS
From 24-SEP-23 10:00:00 to 24-SEP-23 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Brownsville/South Padre Island International Airport Automated Surface Observing System recorded four hours of apparent temperature of 111 or higher, with values peaking at just under 114 degrees between 1 and 2 PM.  Harlingen/Valley International Airport only touched 111 degrees at around 3 PM CDT. Proxies with these locations as well as northern Kenedy/Kleberg County to the north suggest at least 2 hours of 111 degree or higher heat index values across inland Willacy. This was the hottest feeling day of the three-day late-September stretch.

Heat in INLAND KENEDY COUNTY, TEXAS
From 24-SEP-23 11:30:00 to 24-SEP-23 16:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Kingsville Naval Air Station Observation recorded more than five hours of heat index in excess of 111 degrees, peaking at 119 degrees just before 3 PM CDT.  Though the Kingsville site is typically notably higher with heat index values than others, using proxy and extrapolated data among other sites in Cameron and Brooks County suggests values in much of Kenedy County likely reached or exceeded 111 for 3 to 5 hours. Mid to late afternoon east-southeast flow off of the very warm Gulf and Laguna Madre likely fed the spike in heat index.  This was the hottest-feeling day of the late September period.

Heat in BROOKS, TEXAS
From 24-SEP-23 15:30:00 to 24-SEP-23 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Automated Weather Observation Station near Falfurrias (Brooks County) recorded near two hours of heat index values at or above 111 degrees, including 1 hour between 113 and 117 degrees. It is assumed by proxy with observations in northern Kenedy County and at Kingsville Naval Air Station (Kleberg) that locations in eastern Brooks likely reached or exceeded 111 for 2 or more hours; hence the 2.5 hour estimated period of high heat index values. Mid to late afternoon east-southeast flow off of the very warm Gulf and Laguna Madre likely fed the spike in heat index.  This was the hottest-feeling day of the late September period.

Heat in COASTAL CAMERON, TEXAS
From 22-SEP-23 12:45:00 to 22-SEP-23 15:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport Automated Surface Observing System recorded just under three hours of apparent temperature of 111 or higher, with values peaking at 114 degrees.

Heat in COASTAL WILLACY, TEXAS
From 22-SEP-23 12:45:00 to 22-SEP-23 15:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport Automated Surface Observing System recorded just under three hours of apparent temperature of 111 or higher, with values peaking at 114 degrees. By proxy, it can be assumed that Coastal Willacy County also reached at least 111 degrees for a similar period of time.

Heat in COASTAL KENEDY, TEXAS
From 22-SEP-23 12:45:00 to 22-SEP-23 15:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Cameron County Airport Automated Surface Observing System recorded just under three hours of apparent temperature of 111 or higher, with values peaking at 114 degrees. At Kingsville Naval Air Station - a location where heat index values run a bit hot compared with surrounding locations - the apparent temperature reached just below 116 degrees, and was between 113 and 115 between 130 and 430 PM CDT.  Using a lower value based on locations near the coast, it can be assumed that Coastal Kenedy County reached or just exceeded 111 degrees.