NOAA's Center for Operational Oceanographic Products and Services runs gauge 8779770 at Port Isabel. At 2:54 p.m. local time on 18 September 2026 it reported a water temperature of 86.5 degrees Fahrenheit.
The National Weather Service coastal waters forecast issued from Brownsville the same day has east winds around 10 knots over the Laguna Madre from Brownsville to Baffin Bay today, with light chop on the bay, becoming calmer overnight. Through the rest of the week it stays light — 5 to 10 knots, smooth to light chop — with Tuesday the exception at 10 to 15 knots and moderate chop.
On the Gulf side, the same forecast has east winds 5 to 10 knots today with seas of 4 to 5 feet, strengthening to 10 to 15 knots tonight before easing, and seas down to 2 to 3 feet by Sunday. It also notes a chance of showers and thunderstorms on Tuesday, and that winds and seas run higher in and near thunderstorms.
Tide predictions for the same Port Isabel station give Friday a high of 1.81 feet at 1:32 a.m. and a low of 0.35 feet at 3:20 p.m.; Saturday a high of 1.83 feet at 2:58 a.m. and a low of 0.38 feet at 4:30 p.m.; Sunday a high of 1.83 feet at 3:45 a.m. and a low of 0.40 feet at 5:37 p.m. That is under a foot and a half of range on each of the three days.
Every number above is a reading or a prediction published by a federal gauge or forecast office, with the time it was published. None of it is a swimming or wading recommendation, which is a judgement no gauge makes.
Sources: NOAA CO-OPS station 8779770 (Port Isabel), latest water temperature — https://api.tidesandcurrents.noaa.gov/api/prod/datagetter?date=latest&station=8779770&product=water_temperature&units=english&time_zone=lst_ldt&datum=MLLW&format=json · NWS Brownsville coastal waters forecast issued 2026-09-18 18:48Z — https://api.weather.gov/products/38f54625-1203-40c1-9858-4c7f969efd19 · NOAA CO-OPS station 8779770, high/low tide predictions 18-20 September 2026 — https://api.tidesandcurrents.noaa.gov/api/prod/datagetter?product=predictions&application=spi&begin_date=20260918&end_date=20260920&datum=MLLW&station=8779770&time_zone=lst_ldt&units=english&interval=hilo&format=json
