Tides Today & Tomorrow in Port Isabel, TX

TIDE TIMES for Friday, August 21, 2026
The tide is currently falling in Port Isabel, TX.
Next low tide : in 1h 50m at 5:20 pm (0.0 ft)
Next high tide (tomorrow) : 4:23 am (1.6 ft)
Sunset today : 7:59 pm
Sunrise tomorrow : 7:04 am
Moon phase : First Quarter (65% illuminated)
Tide Station Location : Station #8779770
Common Questions About Tides

Port Isabel, TX Tides - May 1996

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed3:521.31:261.19:330.99:060.26:518:00Waxing Gibbous1Wed
2Thu4:431.41:211.110:321.09:390.06:508:01Full Moon2Thu
3Fri5:371.510:14-0.16:498:01Full Moon3Fri
4Sat6:381.510:55-0.26:488:02Full Moon4Sat
5Sun7:401.611:44-0.26:488:02Waning Gibbous5Sun
6Mon8:391.66:478:03Waning Gibbous6Mon
7Tue9:451.612:39-0.26:468:03Waning Gibbous7Tue
8Wed10:481.51:34-0.26:468:04Third Quarter8Wed
9Thu11:251.42:280.06:458:04Third Quarter9Thu
10Fri11:491.39:230.93:310.26:520.96:448:05Third Quarter10Fri
11Sat12:071.24:540.46:510.76:448:06Third Quarter11Sat
12Sun12:051.012:251.16:150.67:170.56:438:06Waning Crescent12Sun
13Mon1:551.112:411.17:410.87:510.36:438:07Waning Crescent13Mon
14Tue3:421.212:531.09:180.98:270.16:428:07Waning Crescent14Tue
15Wed4:441.312:491.010:391.09:020.06:428:08New Moon15Wed
16Thu5:431.49:36-0.16:418:08New Moon16Thu
17Fri6:431.410:09-0.26:418:09New Moon17Fri
18Sat7:331.510:43-0.26:408:09New Moon18Sat
19Sun8:141.411:20-0.16:408:10Waxing Crescent19Sun
20Mon8:531.46:398:10Waxing Crescent20Mon
21Tue9:371.412:02-0.16:398:11Waxing Crescent21Tue
22Wed10:191.312:470.06:398:11Waxing Crescent22Wed
23Thu10:441.21:290.16:388:12First Quarter23Thu
24Fri11:011.22:080.26:388:12First Quarter24Fri
25Sat11:151.110:440.72:480.37:000.76:388:13First Quarter25Sat
26Sun11:271.13:400.56:380.56:378:13First Quarter26Sun
27Mon12:240.811:35 AM1.05:080.76:550.46:378:14Waxing Gibbous27Mon
28Tue1:560.911:36 AM1.06:260.87:210.26:378:14Waxing Gibbous28Tue
29Wed3:241.111:31 AM1.07:580.97:540.06:378:15Waxing Gibbous29Wed
30Thu4:161.28:32-0.26:368:15Waxing Gibbous30Thu
31Fri5:041.49:12-0.46:368:16Full Moon31Fri
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 10:51 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 transitional phase. Tonight's moon is 65% 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 shifting between spring and neap.

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 (65% illuminated). This places Port Isabel, TX in a transitional tide cycle, so tidal ranges are shifting between spring and neap 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