textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 611 PM CDT Tue Sep 1 2026

- Hot temperatures, near record to record-breaking, are expected to continue into Labor Day Weekend. - Widespread Major (Level 3 of 4) to Extreme (Level 4 of 4) Heat Risk of heat-related illness is expected each day. - Isolated sea breeze showers and thunderstorms are possible each afternoon, especially during Labor Day Weekend.

DISCUSSION

Issued at 115 PM CDT Tue Sep 1 2026

It may be the first day of meteorological fall, but the summertime heat and triple-digit high temperatures are here to stay at least through mid September. Deep South Texas will remain under the influence of ridging aloft, maintaining the unseasonably hot and mostly rain-free conditions heading into Labor Day. Expect daily highs ranging from 100-108 degrees, with the exception being along the lower Texas beaches and immediate coast. This is around 5-10 degrees above seasonal normals for early September. Persistent low level southerly to southeasterly flow will maintain elevated humidity, which will result in heat index values ranging from 105-112 degrees. There also wont be much relief from the heat at night, with overnight lows ranging from the mid to upper 70s across the Northern Ranchlands to low 80s across the Rio Grande Valley. All in all, this will result in a major (level 3 of 4) to extreme (level 4 of 4) heat risk across all of Deep South Texas.

The oppressive heat will continue heading into Labor Day weekend, but there may be a small opportunity for isolated sea breeze convection beginning Saturday. Low rain chances (around 20% or less) are confined mainly along and east of US-281 this weekend and Labor Day. Taking a look at some Labor Day climatology statistics, the chance of receiving at greater than or equal to 0.01 inches of rain on Labor Day is 33% for Brownsville International Airport, 45% for Harlingen International Airport, and 25% for McAllen International Airport. Well take what we can get!

AVIATION

(00Z TAFS) Issued at 611 PM CDT Tue Sep 1 2026

VFR conditions prevail. Breezy southeasterly winds begin to diminish to 5-10 kts this evening. Mid to late Wednesday morning, gusts to 20-25 kts return.

MARINE

Issued at 115 PM CDT Tue Sep 1 2026

Generally favorable marine conditions will continue through the forecast period with low seas and light to moderate southeasterly winds. Intermittent Small Craft Exercise Caution conditions cannot be ruled out each afternoon along the Laguna Madre and nearshore Gulf waters. An isolated shower or storm is possible each day over the Gulf waters.

CLIMATE

Issued at 115 PM CDT Tue Sep 1 2026

Near record to record breaking temperatures are expected through at least early September. Here are the daily records for Brownsville, Harlingen, and McAllen through this Friday.

Tuesday, September 1

Brownsville: 100F (2023, 2020) Harlingen: 103F (1928, 1952) McAllen: 106F (2018)

Wednesday, September 2

Brownsville: 99F (2018) Harlingen: 104F (1928, 1937) McAllen: 106F (2018)

Thursday, September 3

Brownsville: 102F (2011) Harlingen: 106F (2011) McAllen: 106F (2011)

Friday, September 4

Brownsville: 103F (2011, 2000) Harlingen: 107F (2011) McAllen: 108F (2011)

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 81 99 81 98 / 0 0 0 0 HARLINGEN 77 103 78 102 / 0 0 0 0 MCALLEN 81 105 81 104 / 0 0 0 0 RIO GRANDE CITY 79 106 79 105 / 0 0 0 0 SOUTH PADRE ISLAND 82 90 82 90 / 0 0 0 0 BAYVIEW/PORT ISABEL 79 97 80 97 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

TX...None. GM...None.