Tides Today & Tomorrow in Port Isabel, TX

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently rising in Port Isabel, TX.
Next low tide : 2:34 pm (0.2 ft)
Next high tide : in 1h 29m at 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 - Apr 2004

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu3:281.36:100.16:196:45Waxing Gibbous1Thu
2Fri3:141.27:090.28:311.06:186:46Waxing Gibbous2Fri
3Sat12:481.13:041.18:070.38:360.86:176:46Waxing Gibbous3Sat
4Sun3:231.23:591.010:010.59:540.57:167:47Full Moon4Sun
5Mon4:331.33:511.010:590.710:210.37:147:47Full Moon5Mon
6Tue5:461.53:341.012:210.97:137:48Full Moon6Tue
7Wed7:081.611:42-0.27:127:48Waning Gibbous7Wed
8Thu8:311.67:117:49Waning Gibbous8Thu
9Fri10:251.712:36-0.37:107:49Waning Gibbous9Fri
10Sat12:031.71:32-0.47:097:50Third Quarter10Sat
11Sun1:181.72:30-0.37:087:50Third Quarter11Sun
12Mon2:341.63:39-0.27:077:51Third Quarter12Mon
13Tue3:201.55:02-0.17:067:51Third Quarter13Tue
14Wed3:391.46:180.17:057:52Waning Crescent14Wed
15Thu3:321.27:310.39:050.97:047:52Waning Crescent15Thu
16Fri1:241.13:161.18:440.59:060.77:037:53Waning Crescent16Fri
17Sat3:111.23:121.09:470.69:230.57:037:53New Moon17Sat
18Sun4:241.33:101.010:480.89:460.37:027:54New Moon18Sun
19Mon5:291.42:531.012:411.07:017:54New Moon19Mon
20Tue6:401.510:390.07:007:55New Moon20Tue
21Wed7:441.511:12-0.16:597:55Waxing Crescent21Wed
22Thu8:441.511:51-0.16:587:56Waxing Crescent22Thu
23Fri10:131.56:577:56Waxing Crescent23Fri
24Sat11:311.612:37-0.16:567:57Waxing Crescent24Sat
25Sun12:231.51:25-0.16:557:57First Quarter25Sun
26Mon1:131.52:130.06:557:58First Quarter26Mon
27Tue2:011.53:050.16:547:58First Quarter27Tue
28Wed2:261.44:110.26:537:59First Quarter28Wed
29Thu2:181.35:230.36:527:59Waxing Gibbous29Thu
30Fri2:061.26:270.48:180.86:518:00Waxing Gibbous30Fri
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8779770)

Common Questions About Port Isabel, TX Tides

Show All
What time does the tide turn (slack tide) in Port Isabel, TX today?

Slack tide in Port Isabel, TX is approximately 9:43 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