Tides Today & Tomorrow in Alcatraz Island, CA

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently falling in Alcatraz Island, CA.
Next low tide : in 5h 23m at 11:32 pm (1.1 ft)
Next high tide (tomorrow) : 6:15 am (3.9 ft)
Sunset today : 7:58 pm
Sunrise tomorrow : 6:28 am
Moon phase : First Quarter (37% illuminated)
Tide Station Location : Station #9414792
Common Questions About Tides

Alcatraz Island, CA Tides - Sep 1941

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon9:034.98:076.32:030.02:012.55:396:39Waxing Gibbous1Mon
2Tue9:515.29:036.32:55-0.12:582.25:406:38Waxing Gibbous2Tue
3Wed10:325.49:546.23:41-0.23:482.05:416:36Waxing Gibbous3Wed
4Thu11:105.510:426.14:23-0.14:331.75:426:35Full Moon4Thu
5Fri11:455.611:275.95:010.15:161.55:426:33Full Moon5Fri
6Sat12:175.65:370.35:571.45:436:32Full Moon6Sat
7Sun12:105.612:475.66:120.76:361.35:446:30Waning Gibbous7Sun
8Mon12:545.31:175.56:461.17:171.25:456:29Waning Gibbous8Mon
9Tue1:385.01:485.57:211.57:591.25:466:27Waning Gibbous9Tue
10Wed2:274.62:215.47:592.08:461.35:476:26Waning Gibbous10Wed
11Thu3:234.33:005.38:412.49:411.35:476:24Third Quarter11Thu
12Fri4:314.13:465.29:352.810:451.35:486:22Third Quarter12Fri
13Sat5:534.04:425.210:443.011:531.25:496:21Third Quarter13Sat
14Sun7:114.15:455.212:013.15:506:19Third Quarter14Sun
15Mon8:094.46:475.312:551.01:052.95:516:18Waning Crescent15Mon
16Tue8:514.67:445.51:470.71:572.75:526:16Waning Crescent16Tue
17Wed9:274.98:375.72:310.52:422.35:536:15Waning Crescent17Wed
18Thu10:015.19:275.93:110.33:231.95:536:13Waning Crescent18Thu
19Fri10:335.410:166.03:490.24:041.55:546:12New Moon19Fri
20Sat11:075.711:066.04:270.24:461.05:556:10New Moon20Sat
21Sun11:415.911:565.95:050.45:300.65:566:08New Moon21Sun
22Mon12:186.15:450.76:170.35:576:07Waxing Crescent22Mon
23Tue12:505.712:576.36:271.17:070.05:586:05Waxing Crescent23Tue
24Wed1:475.41:406.37:121.58:020.05:596:04Waxing Crescent24Wed
25Thu2:515.02:286.28:032.09:030.05:596:02Waxing Crescent25Thu
26Fri4:024.83:246.09:042.410:120.16:006:01First Quarter26Fri
27Sat5:214.74:295.810:202.711:260.26:015:59First Quarter27Sat
28Sun6:394.85:415.711:462.76:025:58First Quarter28Sun
29Mon7:445.06:535.612:360.21:012.56:035:56Waxing Gibbous29Mon
30Tue8:365.27:585.61:370.22:042.16:045:54Waxing Gibbous30Tue
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (9414792)

Common Questions About Alcatraz Island, CA Tides

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What time does the tide turn (slack tide) in Alcatraz Island, CA today?

Slack tide in Alcatraz Island, CA is approximately 2:53 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 Alcatraz Island, CA?

Alcatraz Island, CA 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 Alcatraz Island, CA 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 Alcatraz Island, CA?

Tide predictions for Alcatraz Island, CA 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 Alcatraz Island, CA?

Tide data for Alcatraz Island, CA is sourced from NOAA Station #9414792. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=9414792.

What is the moon phase in Alcatraz Island, CA tonight?

Tonight the moon over Alcatraz Island, CA is First Quarter (37% illuminated). This places Alcatraz Island, CA 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