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 5h 20m 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 - Oct 1996

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue10:481.81:060.57:217:15Waning Gibbous1Tue
2Wed1:540.57:217:14Third Quarter2Wed
3Thu12:031.82:430.57:227:13Third Quarter3Thu
4Fri12:581.83:400.67:227:12Third Quarter4Fri
5Sat1:561.74:490.77:237:10Third Quarter5Sat
6Sun2:421.75:520.87:237:09Waning Crescent6Sun
7Mon3:001.611:51 AM1.49:321.46:460.87:247:08Waning Crescent7Mon
8Tue2:541.61:031.48:521.37:410.97:247:07Waning Crescent8Tue
9Wed2:511.52:191.58:491.28:351.07:257:06Waning Crescent9Wed
10Thu2:571.53:231.69:061.09:231.17:257:05New Moon10Thu
11Fri3:051.54:151.69:290.910:071.27:267:04New Moon11Fri
12Sat3:111.55:061.79:560.810:551.37:267:03New Moon12Sat
13Sun3:121.56:041.810:260.67:277:02New Moon13Sun
14Mon3:121.57:081.812:001.411:01 AM0.57:277:01Waxing Crescent14Mon
15Tue8:131.911:440.47:287:00Waxing Crescent15Tue
16Wed9:301.912:340.47:286:59Waxing Crescent16Wed
17Thu11:071.91:260.47:296:59Waxing Crescent17Thu
18Fri11:571.92:190.47:296:58First Quarter18Fri
19Sat3:190.57:306:57First Quarter19Sat
20Sun12:301.84:360.67:306:56First Quarter20Sun
21Mon12:541.75:530.77:316:55Waxing Gibbous21Mon
22Tue1:141.612:091.57:221.37:040.97:316:54Waxing Gibbous22Tue
23Wed1:331.51:451.67:481.18:201.07:326:53Waxing Gibbous23Wed
24Thu1:531.53:161.78:230.89:311.27:336:52Waxing Gibbous24Thu
25Fri2:131.54:241.89:000.610:331.37:336:52Full Moon25Fri
26Sat2:301.55:281.89:370.511:551.47:346:51Full Moon26Sat
27Sun1:401.55:391.99:140.46:345:50Full Moon27Sun
28Mon6:471.99:530.36:355:49Waning Gibbous28Mon
29Tue7:511.810:370.36:365:49Waning Gibbous29Tue
30Wed9:191.811:240.36:365:48Waning Gibbous30Wed
31Thu10:221.812:110.46:375:47Waning Gibbous31Thu
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