Tides Today & Tomorrow in Port Isabel, TX

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently falling in Port Isabel, TX.
Next low tide : in 1h 57m at 2:43 am (1.1 ft)
Next high tide : 4:52 am (1.1 ft)
Sunset today : 8:02 pm
Sunrise tomorrow : 7:03 am
Moon phase : First Quarter (37% illuminated)
Tide Station Location : Station #8779770
Common Questions About Tides

Port Isabel, TX Tides - Jul 2004

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu6:401.69:16-1.06:408:25Full Moon1Thu
2Fri7:411.710:09-0.96:408:25Full Moon2Fri
3Sat8:331.611:04-0.86:418:25Full Moon3Sat
4Sun9:201.56:418:24Waning Gibbous4Sun
5Mon9:531.312:04-0.76:428:24Waning Gibbous5Mon
6Tue9:581.11:02-0.46:428:24Waning Gibbous6Tue
7Wed9:501.07:440.71:54-0.13:500.76:428:24Third Quarter7Wed
8Thu9:490.910:530.72:430.24:290.46:438:24Third Quarter8Thu
9Fri9:470.93:450.65:090.26:438:24Third Quarter9Fri
10Sat2:000.99:10 AM0.96:070.85:45-0.16:448:24Third Quarter10Sat
11Sun3:511.16:20-0.26:448:24Waning Crescent11Sun
12Mon4:381.36:56-0.36:458:23Waning Crescent12Mon
13Tue5:231.47:36-0.46:458:23Waning Crescent13Tue
14Wed6:121.48:18-0.56:468:23Waning Crescent14Wed
15Thu7:001.49:00-0.56:468:23New Moon15Thu
16Fri7:421.49:39-0.56:478:22New Moon16Fri
17Sat8:181.410:17-0.46:478:22New Moon17Sat
18Sun8:471.310:54-0.46:488:22New Moon18Sun
19Mon9:051.311:33-0.36:488:21Waxing Crescent19Mon
20Tue9:011.26:498:21Waxing Crescent20Tue
21Wed8:511.112:15-0.16:498:21Waxing Crescent21Wed
22Thu8:461.06:320.712:580.13:130.76:508:20Waxing Crescent22Thu
23Fri8:391.09:310.71:390.33:310.46:508:20First Quarter23Fri
24Sat8:190.92:180.64:030.26:518:19First Quarter24Sat
25Sun12:050.97:47 AM1.03:010.94:45-0.16:518:19First Quarter25Sun
26Mon3:251.25:31-0.36:528:18First Quarter26Mon
27Tue4:091.46:20-0.56:528:18Waxing Gibbous27Tue
28Wed4:561.67:15-0.76:538:17Waxing Gibbous28Wed
29Thu5:531.78:14-0.86:538:17Waxing Gibbous29Thu
30Fri6:541.79:12-0.76:548:16Full Moon30Fri
31Sat7:411.610:07-0.66:548:15Full Moon31Sat
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 3:47 am — 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 37% 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 (37% 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