Tides Today & Tomorrow in Alcatraz Island, CA

TIDE TIMES for Tuesday, July 21, 2026
The tide is currently rising in Alcatraz Island, CA.
Next low tide : 11:32 am (2.1 ft)
Next high tide : in 5h 18m at 6:24 am (3.8 ft)
Sunset today : 8:27 pm
Sunrise tomorrow : 6:04 am
Moon phase : First Quarter (53% illuminated)
Tide Station Location : Station #9414792
Common Questions About Tides

Alcatraz Island, CA Tides - Jul 1987

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed2:485.05:054.89:420.010:232.95:518:35Waxing Crescent1Wed
2Thu3:374.65:385.010:190.411:282.55:518:35First Quarter2Thu
3Fri4:374.16:125.210:580.95:528:35First Quarter3Fri
4Sat5:563.76:485.512:342.011:42 AM1.55:528:35First Quarter4Sat
5Sun7:333.57:265.91:351.412:322.15:538:35First Quarter5Sun
6Mon9:113.78:086.22:310.71:282.65:538:35Waxing Gibbous6Mon
7Tue10:324.08:546.53:220.02:273.05:548:34Waxing Gibbous7Tue
8Wed11:344.39:446.84:12-0.73:263.25:548:34Waxing Gibbous8Wed
9Thu12:264.65:01-1.24:233.35:558:34Full Moon9Thu
10Fri1:134.85:50-1.65:193.25:568:33Full Moon10Fri
11Sat1:575.06:39-1.86:153.05:568:33Full Moon11Sat
12Sun12:237.12:395.17:26-1.77:142.85:578:33Waning Gibbous12Sun
13Mon1:176.83:215.38:13-1.58:152.55:588:32Waning Gibbous13Mon
14Tue2:126.34:035.58:58-1.09:212.35:588:32Waning Gibbous14Tue
15Wed3:115.74:445.69:43-0.410:321.95:598:31Waning Gibbous15Wed
16Thu4:164.95:275.810:280.411:471.66:008:31Third Quarter16Thu
17Fri5:334.26:116.011:161.26:008:30Third Quarter17Fri
18Sat7:063.86:576.11:011.112:102.06:018:30Third Quarter18Sat
19Sun8:463.87:436.12:080.71:102.66:028:29Waning Crescent19Sun
20Mon10:094.18:306.13:080.32:143.16:038:28Waning Crescent20Mon
21Tue11:124.49:156.23:590.03:143.36:038:28Waning Crescent21Tue
22Wed12:004.64:43-0.24:073.46:048:27Waning Crescent22Wed
23Thu12:414.75:23-0.34:533.46:058:26Waning Crescent23Thu
24Fri1:164.75:59-0.45:343.36:068:25New Moon24Fri
25Sat1:474.76:32-0.46:123.26:078:25New Moon25Sat
26Sun2:154.87:03-0.46:493.06:078:24New Moon26Sun
27Mon12:356.02:414.87:32-0.47:262.96:088:23New Moon27Mon
28Tue1:125.73:074.98:01-0.28:062.76:098:22Waxing Crescent28Tue
29Wed1:505.43:335.08:290.18:502.56:108:21Waxing Crescent29Wed
30Thu2:325.04:015.28:590.59:402.36:118:20Waxing Crescent30Thu
31Fri3:214.64:315.49:311.010:372.06:128:20Waxing Crescent31Fri
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 8:58 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 neap phase. Tonight's moon is 53% 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 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 (53% illuminated). This places Alcatraz Island, CA 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