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 14m 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 - May 2012

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue8:144.39:105.32:281.62:170.66:128:00Waxing Gibbous1Tue
2Wed9:254.59:475.73:180.93:060.86:118:01Waxing Gibbous2Wed
3Thu10:304.610:246.14:050.13:531.16:108:02Waxing Gibbous3Thu
4Fri11:314.811:046.44:52-0.64:391.46:098:03Full Moon4Fri
5Sat12:304.95:39-1.25:261.76:088:04Full Moon5Sat
6Sun1:265.06:27-1.56:152.06:078:05Full Moon6Sun
7Mon12:306.72:224.97:16-1.77:072.26:068:06Waning Gibbous7Mon
8Tue1:176.63:194.98:07-1.68:032.46:058:06Waning Gibbous8Tue
9Wed2:086.34:164.99:00-1.49:062.66:048:07Waning Gibbous9Wed
10Thu3:035.95:154.99:55-1.010:212.66:038:08Waning Gibbous10Thu
11Fri4:035.36:144.910:53-0.511:422.46:028:09Third Quarter11Fri
12Sat5:114.87:105.011:53-0.16:018:10Third Quarter12Sat
13Sun6:284.37:595.21:012.012:520.46:008:11Third Quarter13Sun
14Mon7:484.18:435.42:091.61:470.85:598:12Third Quarter14Mon
15Tue9:034.09:205.53:061.12:371.25:588:13Waning Crescent15Tue
16Wed10:094.19:545.63:540.63:221.55:588:14Waning Crescent16Wed
17Thu11:064.210:245.74:350.24:031.95:578:14Waning Crescent17Thu
18Fri11:564.310:535.85:12-0.14:422.25:568:15Waning Crescent18Fri
19Sat12:414.35:46-0.35:202.45:558:16New Moon19Sat
20Sun1:234.46:19-0.55:562.65:558:17New Moon20Sun
21Mon2:034.46:51-0.66:322.85:548:18New Moon21Mon
22Tue12:275.82:434.47:24-0.67:102.95:538:19New Moon22Tue
23Wed1:025.73:224.47:58-0.67:502.95:538:19Waxing Crescent23Wed
24Thu1:405.54:034.48:35-0.68:363.05:528:20Waxing Crescent24Thu
25Fri2:215.34:454.59:15-0.59:302.95:518:21Waxing Crescent25Fri
26Sat3:075.05:294.69:58-0.310:362.85:518:22Waxing Crescent26Sat
27Sun4:034.66:124.810:460.011:492.45:508:22First Quarter27Sun
28Mon5:104.36:555.111:380.45:508:23First Quarter28Mon
29Tue6:314.07:385.412:591.912:320.85:508:24First Quarter29Tue
30Wed7:573.98:205.82:011.21:281.25:498:25Waxing Gibbous30Wed
31Thu9:184.09:026.22:570.42:231.55:498:25Waxing Gibbous31Thu
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