textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 548 AM 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. - The National Hurricane Center is issuing advisories for Tropical Storm Edouard in the northwestern Gulf. No direct impacts are expected across Deep South Texas, with a potential increase in rip currents along the coast.

DISCUSSION

Issued at 1028 PM CDT Mon Aug 31 2026

September first marks the first day of meteorological fall, but the forecast high temperatures for the period have not gotten the memo. The hot conditions we've had for the past few weeks are expected to continue as ridging in the mid-upper levels dominates the pattern over deep South Texas. High temperatures of 100-106 persist daily (90s near the coast), and overnight low temperatures are expected to remain above normal (80 in the RGV, mid-upper 70s in the Ranchlands), providing little relief from the daytime heat. Widespread Major (level 3 of 4) to Extreme (level 4/4) risk of heat-related illness will continue across the CWA into this weekend. Heat Advisories are possible each day Wednesday through Friday as heat indices peak to 110-115degF.

Skies should be mostly dry through the week. Latest mid-range guidance has backed off of rain chances through Friday, but an isolated afternoon shower or thunderstorm along the sea breeze cannot be ruled out. Rain chances increase into Labor Day weekend as coastal troughing near the surface will support isolated showers and thunderstorms moving inland along the sea breeze. Activity should remain primarily east of US281, with PoPs increasing to 15-25% Saturday and persisting each afternoon through the end of the forecast period.

The National Hurricane Center is issuing advisories for Tropical Storm Edouard in the northwestern Gulf, forecast to make landfall near the TX/LA border Tuesday. There are no impacts to deep S TX at this time, outside of an increased potential for life- threatening rip currents at local beaches.

AVIATION

(12Z TAFS) Issued at 548 AM CDT Tue Sep 1 2026

VFR is anticipated at the aerodromes through the next 24 hours. Breezy daytime winds with higher gusts will become lighter at night. Limited cloud cover and rain-free skies will also occur.

MARINE

Issued at 1028 PM CDT Mon Aug 31 2026

Gentle to moderate south-southeasterly flow with slight seas prevail through the week. Each afternoon, breezy winds will leave choppy conditions on the Bay and nearshore waters. An isolated shower or thunderstorm is possible each day over the Gulf, with chances increasing to 15-30% Saturday into early next week. The National Hurricane Center is issuing advisories for Tropical Storm Edouard in the northwestern Gulf, forecast to make landfall near the TX/LA border in the next day.

CLIMATE

Issued at 1028 PM CDT Mon Aug 31 2026

Record high temperatures may be tied or broken across the Rio Grande Valley this week under strong ridging over Southeastern CONUS. The existing record high temperatures for Brownsville, Harlingen, and McAllen are listed below.

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 99 81 99 81 / 0 0 0 0 HARLINGEN 102 77 103 78 / 0 0 0 0 MCALLEN 104 81 105 81 / 0 0 0 0 RIO GRANDE CITY 105 79 105 79 / 0 0 0 0 SOUTH PADRE ISLAND 90 82 90 82 / 0 0 0 0 BAYVIEW/PORT ISABEL 96 79 97 80 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

None.