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 7h 01m 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 - Feb 1999

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon6:321.09:42-0.57:126:11Full Moon1Mon
2Tue2:370.86:360.912:020.810:27 AM-0.37:126:12Waning Gibbous2Tue
3Wed3:390.86:430.812:150.711:13 AM-0.27:116:13Waning Gibbous3Wed
4Thu4:530.76:540.812:380.511:57 AM0.07:116:14Waning Gibbous4Thu
5Fri6:240.67:030.71:060.412:360.27:106:14Waning Gibbous5Fri
6Sat7:570.66:590.71:370.31:090.47:106:15Third Quarter6Sat
7Sun10:200.76:170.72:160.11:320.67:096:16Third Quarter7Sun
8Mon5:210.83:080.07:096:16Third Quarter8Mon
9Tue3:020.94:03-0.17:086:17Third Quarter9Tue
10Wed3:251.04:53-0.27:076:18Waning Crescent10Wed
11Thu3:521.15:40-0.37:076:19Waning Crescent11Thu
12Fri4:181.16:29-0.37:066:19Waning Crescent12Fri
13Sat4:421.17:18-0.47:056:20Waning Crescent13Sat
14Sun5:011.18:04-0.47:056:21New Moon14Sun
15Mon5:141.18:47-0.410:120.97:046:21New Moon15Mon
16Tue12:330.95:281.09:29-0.410:340.87:036:22New Moon16Tue
17Wed2:220.95:440.910:15-0.211:070.67:026:23New Moon17Wed
18Thu3:330.95:590.911:07-0.111:450.57:016:23Waxing Crescent18Thu
19Fri4:550.96:110.812:030.27:016:24Waxing Crescent19Fri
20Sat6:340.96:180.812:250.312:560.47:006:24Waxing Crescent20Sat
21Sun8:210.96:130.81:070.11:550.76:596:25First Quarter21Sun
22Mon10:581.01:56-0.16:586:26First Quarter22Mon
23Tue1:321.12:56-0.26:576:26First Quarter23Tue
24Wed2:411.24:05-0.36:566:27First Quarter24Wed
25Thu3:241.35:08-0.46:556:27Waxing Gibbous25Thu
26Fri4:021.36:09-0.46:556:28Waxing Gibbous26Fri
27Sat4:341.27:10-0.36:546:29Waxing Gibbous27Sat
28Sun4:541.18:06-0.39:520.96:536:29Full Moon28Sun
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