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 10h 09m 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 - Apr 1997

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue12:361.43:100.06:196:45Third Quarter1Tue
2Wed1:201.34:270.16:186:46Waning Crescent2Wed
3Thu1:421.35:370.17:161.06:176:46Waning Crescent3Thu
4Fri1:591.26:480.27:350.86:166:47Waning Crescent4Fri
5Sat12:511.22:171.17:580.48:050.66:156:47Waning Crescent5Sat
6Sun3:201.33:351.110:000.59:400.47:147:48New Moon6Sun
7Mon4:291.43:521.011:000.710:180.27:137:48New Moon7Mon
8Tue5:381.44:061.012:140.97:127:49New Moon8Tue
9Wed6:531.54:121.11:331.07:117:49Waxing Crescent9Wed
10Thu8:061.57:107:50Waxing Crescent10Thu
11Fri9:291.512:390.07:097:50Waxing Crescent11Fri
12Sat11:151.41:280.07:087:50Waxing Crescent12Sat
13Sun12:151.42:150.17:077:51First Quarter13Sun
14Mon1:051.43:060.27:067:51First Quarter14Mon
15Tue1:531.34:100.37:057:52First Quarter15Tue
16Wed2:231.25:230.49:280.97:047:52First Quarter16Wed
17Thu2:251.16:260.58:590.87:037:53Waxing Gibbous17Thu
18Fri1:061.02:261.17:270.68:490.77:027:53Waxing Gibbous18Fri
19Sat2:271.12:341.08:300.79:000.67:017:54Waxing Gibbous19Sat
20Sun3:311.22:431.09:230.89:200.57:007:54Waxing Gibbous20Sun
21Mon4:201.22:481.010:090.99:450.36:597:55Full Moon21Mon
22Tue5:081.32:431.010:581.010:130.26:587:55Full Moon22Tue
23Wed6:001.42:361.112:091.16:577:56Full Moon23Wed
24Thu6:571.411:200.06:567:56Full Moon24Thu
25Fri7:521.56:567:57Waning Gibbous25Fri
26Sat8:491.512:040.06:557:57Waning Gibbous26Sat
27Sun10:021.512:52-0.16:547:58Waning Gibbous27Sun
28Mon11:101.51:420.06:537:58Third Quarter28Mon
29Tue11:501.52:330.06:527:59Third Quarter29Tue
30Wed12:191.43:370.16:527:59Third Quarter30Wed
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