textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 503 PM CDT Tue Aug 25 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.

- Worsening drought conditions are expected to continue due to the combination of very hot temperatures, antecedent dry conditions, and very high evaporation rates.

- The combination of dry fuels, lowering relative humidity 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; something worth monitoring in the days ahead.

DISCUSSION

Issued at 150 PM CDT Tue Aug 25 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 briefing 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 may be 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 10-15%), but well take what we can get.

AVIATION

(00Z TAFS) Issued at 503 PM CDT Tue Aug 25 2026

Through 00z Thursday...VFR conditions will prevail through the 00z TAF cycle.

Winds will continue out of the south-southeast 5-15 kts through the forecast period. Winds could gusts to between 20-25 kts during the afternoon/evening hours.

MARINE

Issued at 150 PM CDT Tue Aug 25 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 150 PM CDT Tue Aug 25 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.

Tuesday August 25, 2026

Brownsville: 100F in 2019 Harlingen: 103F in 1924 McAllen: 105F in 2019

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 80 99 / 0 0 0 0 HARLINGEN 78 102 77 102 / 0 0 0 0 MCALLEN 80 105 79 105 / 0 0 0 0 RIO GRANDE CITY 78 105 77 105 / 0 0 0 0 SOUTH PADRE ISLAND 81 90 80 90 / 0 0 0 0 BAYVIEW/PORT ISABEL 79 97 78 97 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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