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 11h 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 - Jun 1997

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun2:391.012:031.07:400.87:350.06:368:16Waning Crescent1Sun
2Mon4:091.212:041.09:341.08:16-0.26:368:17Waning Crescent2Mon
3Tue5:081.38:57-0.36:368:17New Moon3Tue
4Wed6:101.49:37-0.46:368:18New Moon4Wed
5Thu7:081.410:15-0.46:368:18New Moon5Thu
6Fri7:531.410:54-0.46:368:18New Moon6Fri
7Sat8:321.411:36-0.36:368:19Waxing Crescent7Sat
8Sun9:081.36:368:19Waxing Crescent8Sun
9Mon9:401.212:20-0.26:368:20Waxing Crescent9Mon
10Tue10:051.21:040.06:368:20Waxing Crescent10Tue
11Wed10:221.11:430.16:368:20First Quarter11Wed
12Thu10:381.010:140.62:180.36:440.66:368:21First Quarter12Thu
13Fri10:511.02:530.46:170.46:368:21First Quarter13Fri
14Sat12:100.710:59 AM0.93:390.66:300.36:368:21First Quarter14Sat
15Sun2:080.810:53 AM0.95:320.86:550.16:368:22Waxing Gibbous15Sun
16Mon3:550.910:28 AM1.06:560.97:26-0.16:368:22Waxing Gibbous16Mon
17Tue4:301.18:02-0.26:368:22Waxing Gibbous17Tue
18Wed5:061.28:40-0.46:368:23Waxing Gibbous18Wed
19Thu5:491.39:19-0.56:378:23Full Moon19Thu
20Fri6:371.410:00-0.56:378:23Full Moon20Fri
21Sat7:201.410:42-0.56:378:23Full Moon21Sat
22Sun7:551.411:31-0.56:378:24Waning Gibbous22Sun
23Mon8:261.36:378:24Waning Gibbous23Mon
24Tue8:541.212:25-0.46:388:24Waning Gibbous24Tue
25Wed9:191.15:440.71:19-0.23:440.76:388:24Waning Gibbous25Wed
26Thu9:431.18:540.72:090.14:230.56:388:24Third Quarter26Thu
27Fri10:041.011:380.73:020.35:060.36:398:24Third Quarter27Fri
28Sat10:230.94:270.65:480.06:398:24Third Quarter28Sat
29Sun2:330.910:37 AM0.96:130.86:29-0.26:398:24Waning Crescent29Sun
30Mon4:041.17:12-0.36:408:24Waning Crescent30Mon
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