Tides Today & Tomorrow in Alcatraz Island, CA

TIDE TIMES for Friday, August 21, 2026
The tide is currently rising in Alcatraz Island, CA.
Next low tide (tomorrow) : 2:49 am (0.6 ft)
Next high tide : in 54m at 7:09 pm (5.5 ft)
Sunset today : 7:54 pm
Sunrise tomorrow : 6:30 am
Moon phase : First Quarter (66% illuminated)
Tide Station Location : Station #9414792
Common Questions About Tides

Alcatraz Island, CA Tides - Nov 1936

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun1:275.212:156.96:072.67:10-1.36:355:11Waning Gibbous1Sun
2Mon2:265.01:066.67:022.88:04-1.06:365:10Waning Gibbous2Mon
3Tue3:275.02:016.18:063.09:02-0.66:375:09Waning Gibbous3Tue
4Wed4:304.93:025.69:233.010:04-0.26:385:08Third Quarter4Wed
5Thu5:315.04:125.010:482.911:070.26:395:07Third Quarter5Thu
6Fri6:275.15:304.612:072.56:405:06Third Quarter6Fri
7Sat7:155.36:494.412:070.61:132.06:415:05Third Quarter7Sat
8Sun7:555.58:024.31:001.02:071.46:425:04Waning Crescent8Sun
9Mon8:295.69:054.41:471.32:530.96:435:03Waning Crescent9Mon
10Tue8:595.810:014.42:291.73:330.56:445:02Waning Crescent10Tue
11Wed9:275.910:504.53:072.14:080.26:465:01Waning Crescent11Wed
12Thu9:545.911:354.63:432.44:41-0.16:475:00New Moon12Thu
13Fri10:216.04:172.75:13-0.36:485:00New Moon13Fri
14Sat12:184.610:51 AM6.04:512.95:46-0.46:494:59New Moon14Sat
15Sun12:594.611:23 AM6.05:253.16:19-0.46:504:58New Moon15Sun
16Mon1:404.611:57 AM5.96:013.26:55-0.46:514:57Waxing Crescent16Mon
17Tue2:234.512:355.76:403.37:35-0.46:524:57Waxing Crescent17Tue
18Wed3:074.51:175.57:263.38:18-0.36:534:56Waxing Crescent18Wed
19Thu3:544.52:065.28:243.39:05-0.16:544:55Waxing Crescent19Thu
20Fri4:404.73:054.99:363.29:560.26:554:55First Quarter20Fri
21Sat5:264.94:184.510:562.810:510.56:564:54First Quarter21Sat
22Sun6:085.25:424.312:092.26:574:54First Quarter22Sun
23Mon6:495.67:084.21:111.46:584:53Waxing Gibbous23Mon
24Tue7:296.08:274.412:421.32:040.66:594:53Waxing Gibbous24Tue
25Wed8:096.49:364.61:351.72:54-0.37:004:52Waxing Gibbous25Wed
26Thu8:516.810:394.82:262.03:43-0.97:014:52Waxing Gibbous26Thu
27Fri9:347.011:365.03:172.34:30-1.47:024:52Full Moon27Fri
28Sat10:207.24:082.65:18-1.67:034:51Full Moon28Sat
29Sun12:305.111:07 AM7.15:002.76:06-1.67:044:51Full Moon29Sun
30Mon1:225.211:56 AM6.95:542.86:55-1.57:054:51Waning Gibbous30Mon
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 10:59 pm — 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 66% 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 (66% 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