textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 130 PM CDT Wed Aug 26 2026

- Very hot, record to near record-breaking temperatures and rain- free conditions are expected to persist through this week.

- Widespread Major (Level 3 of 4) with increasing areas of Extreme (Level 4 of 4) Heat Risk is expected through this week.

- The combination of dry fuels, lowering relative humidity values values, and hot temperatures could lead to elevated fire danger risks through this week.

- Low (20% or less) chances for sea breeze showers/thunderstorms Friday through next weekend, particularly along and east of IH- 69C/US-281.

DISCUSSION

Issued at 130 PM CDT Wed Aug 26 2026

Oppressive summertime heat will continue to be the main weather concern through early September across Deep South Texas as the region remains under the influence of strong high pressure aloft. Temperatures are running around 4-8 degrees above seasonal normals for mid to late August, with near record to record breaking temperatures forecast each afternoon. Widespread triple-digit high temperatures continue region wide through early next week, with the exception being along the immediate coast and islands although highs will still be hot with highs in the 90s. In combination with elevated humidity, heat index values will range from 100-110 degrees each afternoon, with a few areas briefly reaching 111-112 degrees. To add to the oppressive daytime heat, nighttime temperatures also wont provide much relief as it remains seasonably mild with lows in the upper 70s to around 80 degrees with heat indices briefly reaching the mid to upper 80s prior to sunrise. The combination of a prolonged period of triple- digit heat, mild nights, and humidity (among other factors), will result in a major (level 3 of 4) to extreme (level 4 of 4) heat risk for most of the week and into the weekend.

Rain-free conditions unfortunately will continue across Deep South Texas as well. However, there's a glimmer of hope as some guidance indicates isolated showers or storms may develop along the sea breeze Friday through the weekend. Chances are still fairly low (around 10-25%), but well take what we can get!

AVIATION

(18Z TAFS) Issued at 130 PM CDT Wed Aug 26 2026

VFR will prevail through the forecast period at all TAF sites. Expect southerly to southeasterly winds around 10-15 knots with occasional higher gusts through late this evening before falling to around 5-10 knots tonight. Winds should increase once again tomorrow by mid to late morning.

MARINE

Issued at 130 PM CDT Wed Aug 26 2026

Generally favorable marine conditions will continue through the forecast period with low seas and light to moderate southeasterly winds. Brief Small Craft Exercise Caution conditions cannot be ruled out across the Laguna Madre during the late afternoon hours, with occasional gusts near 15-20 knots.

CLIMATE

Issued at 130 PM CDT Wed Aug 26 2026

Near record to record breaking temperatures are expected through the end of August. Here are the daily records for Brownsville, Harlingen, and McAllen through this Friday.

Wednesday August 26, 2026

Brownsville: 101F in 2019 Harlingen: 103F in 1924 and 1948 McAllen: 104F in 2019 and 2018

Thursday August 27, 2026

Brownsville: 102F in 2023 Harlingen: 104F in 1948 McAllen: 105F in 2018

Friday August 28, 2026

Brownsville: 106F in 2023 Harlingen: 106F in 2011 McAllen: 107F in 2023

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 80 99 81 98 / 0 0 0 10 HARLINGEN 76 102 77 101 / 0 0 0 10 MCALLEN 79 104 80 104 / 0 0 0 10 RIO GRANDE CITY 78 104 78 104 / 0 0 0 0 SOUTH PADRE ISLAND 80 89 81 89 / 0 0 0 0 BAYVIEW/PORT ISABEL 78 96 79 96 / 0 0 0 10

BRO WATCHES/WARNINGS/ADVISORIES

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