Tides Today & Tomorrow in Alcatraz Island, CA

TIDE TIMES for Thursday, July 9, 2026
The tide is currently falling in Alcatraz Island, CA.
Next low tide : in 45m at 1:59 am (0.6 ft)
Next high tide : 8:43 am (3.7 ft)
Sunset today : 8:34 pm
Sunrise tomorrow : 5:55 am
Moon phase : Waning Crescent (28% illuminated)
Tide Station Location : Station #9414792
Common Questions About Tides

Alcatraz Island, CA Tides - Sep 1999

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed4:354.64:376.09:591.811:110.86:397:39Third Quarter1Wed
2Thu5:584.45:326.010:592.36:407:38Third Quarter2Thu
3Fri7:284.36:356.112:260.612:132.76:417:36Third Quarter3Fri
4Sat8:494.57:406.21:400.31:302.86:427:35Waning Crescent4Sat
5Sun9:514.88:446.32:450.02:402.76:427:33Waning Crescent5Sun
6Mon10:425.19:436.43:41-0.23:402.46:437:32Waning Crescent6Mon
7Tue11:255.410:376.44:30-0.44:332.16:447:30Waning Crescent7Tue
8Wed12:045.55:14-0.35:211.86:457:29New Moon8Wed
9Thu12:415.65:54-0.26:061.56:467:27New Moon9Thu
10Fri12:166.11:155.66:320.16:501.46:477:26New Moon10Fri
11Sat1:025.81:485.67:090.57:321.26:487:24Waxing Crescent11Sat
12Sun1:485.52:195.67:450.98:151.26:487:23Waxing Crescent12Sun
13Mon2:355.12:515.58:211.49:001.16:497:21Waxing Crescent13Mon
14Tue3:254.73:245.49:001.99:481.26:507:19Waxing Crescent14Tue
15Wed4:244.44:025.39:432.410:441.26:517:18First Quarter15Wed
16Thu5:354.14:475.210:382.911:481.26:527:16First Quarter16Thu
17Fri7:014.15:425.111:513.16:537:15First Quarter17Fri
18Sat8:224.26:455.112:551.11:103.26:537:13First Quarter18Sat
19Sun9:194.47:475.21:570.92:153.16:547:12First Quarter19Sun
20Mon10:004.68:445.42:500.73:052.86:557:10Waxing Gibbous20Mon
21Tue10:344.89:365.63:340.53:472.56:567:09Waxing Gibbous21Tue
22Wed11:055.010:245.74:130.34:262.16:577:07Waxing Gibbous22Wed
23Thu11:355.311:105.84:500.25:031.76:587:05Full Moon23Thu
24Fri12:065.55:250.25:411.36:597:04Full Moon24Fri
25Sat12:375.76:010.36:220.96:597:02Full Moon25Sat
26Sun12:465.81:105.96:390.67:060.57:007:01Full Moon26Sun
27Mon1:375.61:466.17:181.07:530.27:016:59Waning Gibbous27Mon
28Tue2:325.32:256.28:001.48:450.17:026:58Waning Gibbous28Tue
29Wed3:345.03:096.18:472.09:430.17:036:56Waning Gibbous29Wed
30Thu4:444.74:016.09:422.510:490.17:046:55Third Quarter30Thu
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 5:21 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 28% 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 Waning Crescent (28% 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