Tides Today & Tomorrow in Port Isabel, TX

TIDE TIMES for Thursday, August 20, 2026
The tide is currently falling in Port Isabel, TX.
Next low tide : in 8h 00m at 4:19 pm (0.1 ft)
Next high tide (tomorrow) : 3:41 am (1.6 ft)
Sunset today : 8:00 pm
Sunrise tomorrow : 7:03 am
Moon phase : First Quarter (56% illuminated)
Tide Station Location : Station #8779770
Common Questions About Tides

Port Isabel, TX Tides - Mar 1999

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon1:090.94:561.08:53-0.210:000.86:526:30Full Moon1Mon
2Tue2:271.04:550.99:350.010:200.76:516:30Full Moon2Tue
3Wed3:261.05:020.910:180.110:480.56:506:31Full Moon3Wed
4Thu4:240.95:120.811:040.311:210.46:496:31Waning Gibbous4Thu
5Fri5:320.95:170.811:510.511:560.36:486:32Waning Gibbous5Fri
6Sat6:430.95:020.812:350.66:476:32Waning Gibbous6Sat
7Sun7:590.94:260.912:310.21:140.86:466:33Waning Gibbous7Sun
8Mon10:001.01:080.16:456:34Third Quarter8Mon
9Tue11:401.11:500.16:446:34Third Quarter9Tue
10Wed2:021.12:450.06:436:35Third Quarter10Wed
11Thu2:411.23:520.06:426:35Third Quarter11Thu
12Fri3:051.24:540.06:416:36Waning Crescent12Fri
13Sat3:221.25:49-0.16:406:36Waning Crescent13Sat
14Sun3:301.26:46-0.16:396:37Waning Crescent14Sun
15Mon3:381.27:42-0.18:490.96:386:37Waning Crescent15Mon
16Tue12:261.03:491.18:330.09:050.86:376:38New Moon16Tue
17Wed2:081.14:021.09:220.19:300.66:366:38New Moon17Wed
18Thu3:181.24:151.010:160.310:040.46:346:38New Moon18Thu
19Fri4:291.24:260.911:200.510:480.26:336:39Waxing Crescent19Fri
20Sat5:521.34:290.912:270.76:326:39Waxing Crescent20Sat
21Sun7:171.34:141.01:330.96:316:40Waxing Crescent21Sun
22Mon9:111.312:30-0.16:306:40First Quarter22Mon
23Tue11:121.41:22-0.26:296:41First Quarter23Tue
24Wed12:431.42:21-0.26:286:41First Quarter24Wed
25Thu2:011.43:34-0.16:276:42First Quarter25Thu
26Fri2:451.44:480.06:266:42Waxing Gibbous26Fri
27Sat3:121.35:540.19:011.06:256:43Waxing Gibbous27Sat
28Sun3:231.27:000.28:510.96:246:43Waxing Gibbous28Sun
29Mon12:461.13:201.18:000.38:570.86:236:44Waxing Gibbous29Mon
30Tue2:061.13:191.08:490.49:100.76:226:44Full Moon30Tue
31Wed3:061.23:241.09:320.59:290.56:216:45Full 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 10:00 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 neap phase. Tonight's moon is 56% 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 near their weekly minimum.

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 (56% illuminated). This places Port Isabel, TX in a neap tide cycle, so tidal ranges are near their weekly minimum 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