Tides Today & Tomorrow in Alcatraz Island, CA

TIDE TIMES for Wednesday, August 19, 2026
The tide is currently falling in Alcatraz Island, CA.
Next low tide : in 2h 34m at 10:48 am (2.9 ft)
Next high tide : 5:17 pm (5.6 ft)
Sunset today : 7:57 pm
Sunrise tomorrow : 6:28 am
Moon phase : First Quarter (47% illuminated)
Tide Station Location : Station #9414792
Common Questions About Tides

Alcatraz Island, CA Tides - May 1940

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed7:254.18:285.01:481.81:340.85:137:00Waning Crescent1Wed
2Thu8:284.28:595.22:351.32:181.05:127:00Waning Crescent2Thu
3Fri9:224.29:285.33:160.92:571.25:117:01Waning Crescent3Fri
4Sat10:114.39:555.53:530.53:331.45:097:02Waning Crescent4Sat
5Sun10:564.410:245.64:260.24:081.75:087:03New Moon5Sun
6Mon11:404.410:535.74:58-0.14:411.95:077:04New Moon6Mon
7Tue12:234.55:30-0.35:162.15:067:05New Moon7Tue
8Wed1:064.56:04-0.55:522.35:057:06New Moon8Wed
9Thu1:514.56:40-0.66:312.55:047:07Waxing Crescent9Thu
10Fri12:355.72:394.57:19-0.77:162.75:037:08Waxing Crescent10Fri
11Sat1:165.53:304.58:04-0.78:092.85:027:09Waxing Crescent11Sat
12Sun2:035.34:244.58:53-0.59:152.85:017:09Waxing Crescent12Sun
13Mon3:005.05:184.79:48-0.310:332.65:007:10First Quarter13Mon
14Tue4:084.76:114.910:47-0.111:512.15:007:11First Quarter14Tue
15Wed5:274.57:005.211:480.24:597:12First Quarter15Wed
16Thu6:484.47:455.61:001.512:470.54:587:13Waxing Gibbous16Thu
17Fri8:054.48:286.01:590.81:420.84:577:14Waxing Gibbous17Fri
18Sat9:154.69:106.32:510.12:341.14:567:15Waxing Gibbous18Sat
19Sun10:184.79:516.53:41-0.63:241.44:567:15Waxing Gibbous19Sun
20Mon11:164.910:346.64:28-1.04:131.74:557:16Full Moon20Mon
21Tue12:114.95:15-1.35:022.04:547:17Full Moon21Tue
22Wed1:045.06:00-1.45:532.24:547:18Full Moon22Wed
23Thu12:006.31:554.96:46-1.36:452.44:537:19Waning Gibbous23Thu
24Fri12:446.02:474.97:32-1.17:412.64:527:20Waning Gibbous24Fri
25Sat1:305.63:384.88:18-0.78:442.74:527:20Waning Gibbous25Sat
26Sun2:195.14:304.89:06-0.39:542.64:517:21Waning Gibbous26Sun
27Mon3:134.65:204.89:570.111:072.54:517:22Third Quarter27Mon
28Tue4:164.26:084.910:500.54:507:23Third Quarter28Tue
29Wed5:293.96:505.012:152.111:43 AM0.94:507:23Third Quarter29Wed
30Thu6:463.77:285.21:141.712:351.24:497:24Third Quarter30Thu
31Fri8:003.78:025.42:051.21:231.54:497:25Waning 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 2:02 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 neap phase. Tonight's moon is 47% 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 (47% 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