Tides Today & Tomorrow in Port Isabel, TX

TIDE TIMES for Thursday, August 20, 2026
The tide is currently falling in Port Isabel, TX.
Next low tide : in 13h 28m at 4:19 pm (0.1 ft)
Next high tide (tomorrow) : 3:41 am (1.6 ft)
Sunset today : 8:00 pm
Sunrise tomorrow : 7:03 am
Moon phase : First Quarter (56% illuminated)
Tide Station Location : Station #8779770
Common Questions About Tides

Port Isabel, TX Tides - Nov 1999

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon12:071.83:490.56:375:47Third Quarter1Mon
2Tue12:351.710:02 AM1.37:431.35:030.76:385:46Waning Crescent2Tue
3Wed12:461.611:40 AM1.47:221.16:120.96:385:46Waning Crescent3Wed
4Thu12:531.51:151.47:331.07:271.06:395:45Waning Crescent4Thu
5Fri1:021.42:351.57:520.88:341.26:405:44Waning Crescent5Fri
6Sat1:101.33:331.68:140.69:311.36:405:44New Moon6Sat
7Sun1:081.34:251.78:380.56:415:43New Moon7Sun
8Mon5:221.79:030.46:425:43New Moon8Mon
9Tue6:161.79:300.36:425:42New Moon9Tue
10Wed7:051.710:020.36:435:42Waxing Crescent10Wed
11Thu7:561.710:390.36:445:41Waxing Crescent11Thu
12Fri9:041.711:230.36:445:41Waxing Crescent12Fri
13Sat10:031.712:080.36:455:40Waxing Crescent13Sat
14Sun10:361.712:520.46:465:40First Quarter14Sun
15Mon10:581.61:360.46:475:39First Quarter15Mon
16Tue11:171.52:320.56:475:39First Quarter16Tue
17Wed11:341.53:520.66:485:39First Quarter17Wed
18Thu10:501.111:491.46:151.05:070.86:495:38Waxing Gibbous18Thu
19Fri12:281.26:250.86:230.96:505:38Waxing Gibbous19Fri
20Sat12:011.32:021.46:510.67:511.16:505:38Waxing Gibbous20Sat
21Sun12:061.33:091.67:240.39:071.26:515:37Full Moon21Sun
22Mon12:021.34:121.78:030.16:525:37Full Moon22Mon
23Tue5:231.88:44-0.16:525:37Full Moon23Tue
24Wed6:371.89:29-0.36:535:37Full Moon24Wed
25Thu7:451.810:19-0.36:545:37Waning Gibbous25Thu
26Fri9:021.811:16-0.36:555:37Waning Gibbous26Fri
27Sat10:041.712:14-0.26:555:36Waning Gibbous27Sat
28Sun10:381.51:090.06:565:36Third Quarter28Sun
29Mon10:551.42:050.26:575:36Third Quarter29Mon
30Tue11:051.33:150.56:585:36Third Quarter30Tue
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8779770)

Common Questions About Port Isabel, TX Tides

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What time does the tide turn (slack tide) in Port Isabel, TX today?

Slack tide in Port Isabel, TX is approximately 10:00 pm — midway between the next high and low tide, when tidal current is weakest. This is the preferred window for boat crossings, underwater visibility, and fishing in areas with strong currents.

Is this week a spring tide or neap tide in Port Isabel, TX?

Port Isabel, TX is currently in a neap phase. Tonight's moon is 56% illuminated. Spring tides (largest swings) occur near new and full moons; neap tides (smallest swings) occur near first and third quarter moons. Tidal ranges this week are near their weekly minimum.

What datum are Port Isabel, TX tide heights measured from?

Tide heights on this page are measured from Mean Lower Low Water (MLLW), the U.S. NOAA standard. A height of 0 ft represents the 19-year average of each day's lower low tide. Negative values indicate a "minus tide" — water levels below that long-term reference.

What factors can affect the tide predictions for Port Isabel, TX?

Tide predictions for Port Isabel, TX come from NOAA's harmonic analysis and are typically accurate within about ±10 minutes on timing and ±0.5 ft on height. Actual water levels can deviate further due to sustained winds, atmospheric pressure changes, river flow, and storm surge. During major weather events, be sure to check US Harbors weather pages for factors that could impact tidal predictions.

Which NOAA station provides tide data for Port Isabel, TX?

Tide data for Port Isabel, TX is sourced from NOAA Station #8779770. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=8779770.

What is the moon phase in Port Isabel, TX tonight?

Tonight the moon over Port Isabel, TX is First Quarter (56% illuminated). This places Port Isabel, TX in a neap tide cycle, so tidal ranges are near their weekly minimum this week.

US Harbors Tidal Data

The data in our tide charts, tide tables, and tide graphs is provided by NOAA and others. These predictions are derived mathematically from numerous inputs, including data from historical tide stations and nearby locations where sensors are actively recording. As shown in the tide graph at the top of this page, “Predicted” tides (blue) are what forecasting models expect to happen. “Observed” tides (red) are those recorded by local sensors in real time, overlaid on the predictions for direct comparison. We display Observed water levels for a select group of harbors including Portland, Maine, where a physical sensor monitors water levels in real time.

LEARN MORE ABOUT OUR TIDE DATA