The combination of northwesterly flow well above the earth's surface - ahead of building mid and upper level high pressure - with a retreating/dissipating surface front in South and Central Texas, brought enhanced surface moisture along with near record to record heat across the Rio Grande Valley counties of Deep South Texas between July 6th and 9th.  Daytime heat index values reached or exceeded 111 for several hours during the period, with early morning lows generally remaining near or just above 80, mainly close to the Rio Grande River.

Heat in CAMERON, TEXAS
From 06-JUL-09 14:00:00 to 09-JUL-09 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Surface observations and extrapolated data generally along and south of Federal Highway 83 west of Harlingen and Brownsville, indicated several hours of daytime heat index at or above 111F and early morning low temperatures remaining above 80F.  Near the Rio Grande, observations indicated between 2 and 5 hours of high heat index values each afternoon; values peaked at 115 at the Lower Rio Grande Valley National Wildlife Refuge along the southwest Cameron County/southeast Hidalgo County line on the 7th at around 4 PM CDT.  As of this writing, there were no known fatalities in Cameron County during this event.

Heat in ZAPATA, TEXAS
From 06-JUL-09 11:00:00 to 09-JUL-09 17:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Surface observations and extrapolated data generally along and near the Rio Grande in southwestern Starr County, generally along and west of Highway 83 south of the City of Zapata, indicated several hours of daytime heat index at or above 111F and early morning low temperatures remaining above 80F.  Observations indicated between 3 and 6 hours of high heat index values each afternoon; values peaked between 115 and 120F at the Falcon Lake Real-time Observation Monitor and Analysis Network site near the Starr/Zapata County line.  Peak values generally occurred between 3 and 5 PM CDT. As of this writing, there were no known fatalities in Zapata County during this event.

Heat in HIDALGO, TEXAS
From 06-JUL-09 14:00:00 to 09-JUL-09 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Surface observations generally along and south of Federal Highway 83, including the McAllen/Mission area, indicated several hours of daytime heat index at or above 111F and early morning low temperatures remaining above 80F.  Near the Rio Grande, observations indicated between 2 and 5 hours of high heat index values each afternoon; values peaked at 115 at the Lower Rio Grande Valley National Wildlife Refuge along the southwest Cameron County/southeast Hidalgo County line on the 7th, and 116 at the McAllen/Miller Airport, around 4 PM CDT.  Record high temperatures were tied on the 6th and set on the 7th through 9th. As of this writing, there were no known fatalities in Hidalgo County during this event.

Heat in STARR, TEXAS
From 06-JUL-09 11:00:00 to 09-JUL-09 17:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Surface observations and extrapolated data generally in and near the populated portion of Starr County (along Highway 83) indicated several hours of daytime heat index at or above 111F and early morning low temperatures remaining above 80F.  Near the Rio Grande, observations indicated between 3 and 6 hours of high heat index values each afternoon; values peaked between 115 and 120F at the Falcon Lake Real-time Observation Monitor and Analysis Network site near the Starr/Zapata County line.  Peak values generally occurred between 3 and 5 PM CDT. As of this writing, there were no known fatalities in Starr County during this event.