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 8h 45m 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 - Mar 1997

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat11:031.04:521.01:500.02:201.06:516:30Third Quarter1Sat
2Sun2:011.12:45-0.16:506:31Third Quarter2Sun
3Mon2:371.23:53-0.26:496:31Third Quarter3Mon
4Tue3:001.24:57-0.26:486:32Waning Crescent4Tue
5Wed3:141.25:58-0.36:476:32Waning Crescent5Wed
6Thu3:231.27:02-0.38:241.06:466:33Waning Crescent6Thu
7Fri3:351.18:03-0.28:420.86:456:33New Moon7Fri
8Sat1:291.13:501.08:59-0.19:120.66:446:34New Moon8Sat
9Sun2:511.14:080.99:540.19:490.46:436:34New Moon9Sun
10Mon4:021.24:260.910:540.310:350.26:426:35Waxing Crescent10Mon
11Tue5:201.24:440.911:590.611:270.16:416:35Waxing Crescent11Tue
12Wed6:441.24:550.912:590.86:406:36Waxing Crescent12Wed
13Thu8:161.24:360.912:180.02:040.96:396:36Waxing Crescent13Thu
14Fri10:371.21:07-0.16:386:37First Quarter14Fri
15Sat12:051.21:590.06:376:37First Quarter15Sat
16Sun1:361.23:020.06:366:38First Quarter16Sun
17Mon2:301.24:130.16:356:38First Quarter17Mon
18Tue3:041.25:150.16:346:39Waxing Gibbous18Tue
19Wed3:251.16:130.29:130.96:336:39Waxing Gibbous19Wed
20Thu3:291.17:090.28:560.86:326:40Waxing Gibbous20Thu
21Fri12:551.03:211.07:580.38:530.86:316:40Waxing Gibbous21Fri
22Sat2:041.03:201.08:380.49:040.76:306:41Full Moon22Sat
23Sun2:571.13:261.09:160.59:240.56:296:41Full Moon23Sun
24Mon3:441.13:321.09:540.69:500.46:286:42Full Moon24Mon
25Tue4:351.13:341.010:400.710:220.36:266:42Full Moon25Tue
26Wed5:341.23:311.011:370.810:590.26:256:43Waning Gibbous26Wed
27Thu6:351.23:291.012:320.96:246:43Waning Gibbous27Thu
28Fri7:391.33:271.11:241.06:236:43Waning Gibbous28Fri
29Sat9:081.312:230.16:226:44Waning Gibbous29Sat
30Sun10:411.31:080.06:216:44Third Quarter30Sun
31Mon11:401.42:000.06:206:45Third Quarter31Mon
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