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 3h 24m 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 - Jul 1996

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon6:591.410:28-0.76:408:25Full Moon1Mon
2Tue7:331.311:21-0.56:408:25Full Moon2Tue
3Wed7:581.36:418:25Waning Gibbous3Wed
4Thu8:201.24:530.912:18-0.32:150.86:418:24Waning Gibbous4Thu
5Fri8:411.17:100.71:15-0.12:510.66:428:24Waning Gibbous5Fri
6Sat9:011.09:240.72:060.23:390.46:428:24Third Quarter6Sat
7Sun9:220.92:580.54:350.26:428:24Third Quarter7Sun
8Mon12:100.89:40 AM0.94:210.75:270.06:438:24Third Quarter8Mon
9Tue3:031.09:46 AM0.96:250.96:12-0.26:438:24Waning Crescent9Tue
10Wed4:071.16:55-0.36:448:24Waning Crescent10Wed
11Thu4:521.27:37-0.36:448:24Waning Crescent11Thu
12Fri5:381.38:19-0.36:458:23Waning Crescent12Fri
13Sat6:251.38:58-0.36:458:23New Moon13Sat
14Sun7:051.39:33-0.36:468:23New Moon14Sun
15Mon7:351.210:07-0.36:468:23New Moon15Mon
16Tue7:511.210:40-0.26:478:22New Moon16Tue
17Wed7:491.111:15-0.16:478:22New Moon17Wed
18Thu7:481.111:530.06:488:22Waxing Crescent18Thu
19Fri7:551.04:310.72:220.76:488:21Waxing Crescent19Fri
20Sat8:051.06:310.712:330.22:410.66:488:21Waxing Crescent20Sat
21Sun8:131.08:420.71:110.33:110.56:498:21Waxing Crescent21Sun
22Mon8:141.011:100.71:430.53:490.36:498:20First Quarter22Mon
23Tue8:091.02:070.74:330.16:508:20First Quarter23Tue
24Wed8:081.05:19-0.16:508:19First Quarter24Wed
25Thu8:061.16:04-0.26:518:19Waxing Gibbous25Thu
26Fri4:231.26:51-0.46:518:18Waxing Gibbous26Fri
27Sat4:501.37:43-0.56:528:18Waxing Gibbous27Sat
28Sun5:211.48:38-0.56:528:17Waxing Gibbous28Sun
29Mon5:511.49:31-0.56:538:17Full Moon29Mon
30Tue6:151.31:131.210:531.210:21-0.46:538:16Full Moon30Tue
31Wed6:331.23:131.111:301.011:14-0.26:548:15Full Moon31Wed
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