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 57m 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 1997

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu12:421.35:000.37:110.96:518:00Third Quarter1Thu
2Fri1:031.26:180.57:290.76:508:01Waning Crescent2Fri
3Sat1:111.11:231.17:370.68:010.46:498:01Waning Crescent3Sat
4Sun2:521.21:431.19:010.88:380.26:498:02Waning Crescent4Sun
5Mon4:071.41:591.110:130.99:160.06:488:02New Moon5Mon
6Tue5:111.52:051.111:361.19:55-0.16:478:03New Moon6Tue
7Wed6:201.510:35-0.26:478:03New Moon7Wed
8Thu7:271.611:17-0.26:468:04Waxing Crescent8Thu
9Fri8:251.56:458:04Waxing Crescent9Fri
10Sat9:271.512:04-0.16:458:05Waxing Crescent10Sat
11Sun10:381.412:52-0.16:448:05Waxing Crescent11Sun
12Mon11:221.41:370.16:438:06First Quarter12Mon
13Tue11:471.32:200.26:438:06First Quarter13Tue
14Wed12:011.23:060.36:428:07First Quarter14Wed
15Thu12:121.14:080.57:540.76:428:08First Quarter15Thu
16Fri12:020.812:231.15:250.67:340.66:418:08Waxing Gibbous16Fri
17Sat1:270.912:301.06:310.87:470.46:418:09Waxing Gibbous17Sat
18Sun3:011.012:301.07:460.98:110.36:408:09Waxing Gibbous18Sun
19Mon3:591.212:151.09:091.08:400.16:408:10Waxing Gibbous19Mon
20Tue4:441.39:110.06:408:10Full Moon20Tue
21Wed5:301.49:43-0.26:398:11Full Moon21Wed
22Thu6:221.410:18-0.26:398:11Full Moon22Thu
23Fri7:151.510:57-0.36:388:12Full Moon23Fri
24Sat8:021.511:42-0.36:388:12Waning Gibbous24Sat
25Sun8:491.56:388:13Waning Gibbous25Sun
26Mon9:391.512:34-0.36:378:13Waning Gibbous26Mon
27Tue10:231.41:26-0.26:378:14Third Quarter27Tue
28Wed10:531.32:170.06:378:14Third Quarter28Wed
29Thu11:151.210:250.83:140.26:070.76:378:15Third Quarter29Thu
30Fri11:341.14:370.46:260.46:378:15Third Quarter30Fri
31Sat12:300.911:50 AM1.06:060.76:570.26:368:16Waning Crescent31Sat
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