Tides Today & Tomorrow in Alcatraz Island, CA

TIDE TIMES for Saturday, July 18, 2026
The tide is currently falling in Alcatraz Island, CA.
Next low tide : in 4h 46m at 10:04 pm (1.9 ft)
Next high tide (tomorrow) : 3:48 am (4.9 ft)
Sunset today : 8:29 pm
Sunrise tomorrow : 6:02 am
Moon phase : Waxing Crescent (24% illuminated)
Tide Station Location : Station #9414792
Common Questions About Tides

Alcatraz Island, CA Tides - Dec 1987

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue8:226.39:384.41:431.53:080.17:064:51Waxing Gibbous1Tue
2Wed8:586.510:404.62:302.03:52-0.47:074:50Waxing Gibbous2Wed
3Thu9:326.511:364.73:162.54:33-0.87:084:50Full Moon3Thu
4Fri10:076.54:002.95:12-0.97:094:50Full Moon4Fri
5Sat12:284.810:41 AM6.44:453.25:50-0.97:094:50Full Moon5Sat
6Sun1:154.811:17 AM6.25:293.46:27-0.87:104:50Full Moon6Sun
7Mon2:014.811:53 AM6.06:133.57:06-0.77:114:50Waning Gibbous7Mon
8Tue2:444.712:325.86:583.57:45-0.57:124:50Waning Gibbous8Tue
9Wed3:274.61:135.57:483.58:26-0.27:134:50Waning Gibbous9Wed
10Thu4:094.61:585.18:463.49:080.17:144:50Waning Gibbous10Thu
11Fri4:494.62:504.69:553.39:520.47:144:50Third Quarter11Fri
12Sat5:264.83:534.211:083.010:370.87:154:51Third Quarter12Sat
13Sun6:015.05:113.812:142.57:164:51Third Quarter13Sun
14Mon6:345.26:393.71:101.97:174:51Third Quarter14Mon
15Tue7:065.58:053.712:121.71:561.27:174:51Waning Crescent15Tue
16Wed7:405.99:194.01:002.22:380.57:184:52Waning Crescent16Wed
17Thu8:156.210:214.31:472.63:19-0.27:194:52Waning Crescent17Thu
18Fri8:526.511:164.52:352.94:00-0.87:194:52Waning Crescent18Fri
19Sat9:346.83:223.14:43-1.27:204:53New Moon19Sat
20Sun12:064.710:18 AM6.94:103.35:28-1.67:204:53New Moon20Sun
21Mon12:534.811:06 AM7.05:003.36:15-1.77:214:54New Moon21Mon
22Tue1:404.911:57 AM6.95:523.27:03-1.67:214:54Waxing Crescent22Tue
23Wed2:255.012:506.66:503.17:51-1.37:224:55Waxing Crescent23Wed
24Thu3:115.11:476.17:552.98:40-0.97:224:55Waxing Crescent24Thu
25Fri3:575.22:505.49:092.69:30-0.37:234:56First Quarter25Fri
26Sat4:435.54:044.710:312.210:210.47:234:56First Quarter26Sat
27Sun5:295.75:334.111:511.611:151.27:234:57First Quarter27Sun
28Mon6:146.07:103.91:031.07:244:58First Quarter28Mon
29Tue6:596.28:404.012:121.92:040.37:244:58Waxing Gibbous29Tue
30Wed7:426.39:524.31:112.52:57-0.27:244:59Waxing Gibbous30Wed
31Thu8:256.410:504.62:082.93:42-0.57:255:00Waxing 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 12:56 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 24% 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 Waxing Crescent (24% 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