Alcatraz Island, CA Weather Forecast and Current Conditions

Day Sky High / Low Precip Wind Humidity
Mon
Aug 10 		Partly Cloudy
Close Hourly 		66º / 57º 15% SW 17 mph 81%
7am Mostly Cloudy 58º 15% SW 7 mph 91%
8am Cloudy 59º 15% SSW 8 mph 90%
9am Cloudy 60º 6% SW 9 mph 87%
10am Mostly Cloudy 61º 5% SW 11 mph 87%
11am Mostly Cloudy 62º 5% SW 13 mph 84%
12pm Partly Cloudy 64º 5% SW 14 mph 80%
1pm Partly Cloudy 65º 5% WSW 15 mph 79%
2pm Partly Cloudy 65º 9% SW 16 mph 76%
3pm Mostly Cloudy 66º 9% SW 17 mph 74%
4pm Partly Cloudy 66º 5% SW 17 mph 73%
5pm Partly Cloudy 66º 5% SW 16 mph 73%
6pm Partly Cloudy 64º 10% SW 16 mph 76%
7pm Partly Cloudy 63º 8% SW 15 mph 80%
8pm Partly Cloudy 61º 16% SW 14 mph 86%
9pm Partly Cloudy 60º 14% SW 12 mph 89%
10pm Mostly Cloudy 59º 17% SW 12 mph 91%
11pm Mostly Cloudy 59º 17% SW 11 mph 93%
Tue
Aug 11 		Partly Cloudy
View Hourly 		67º / 57º 22% SW 16 mph 81%
12am Mostly Cloudy 59º 23% SW 10 mph 91%
1am Cloudy 58º 24% SW 9 mph 93%
2am Cloudy 58º 19% SW 9 mph 94%
3am Cloudy 58º 15% SW 9 mph 93%
4am Mostly Cloudy 58º 20% SSW 9 mph 93%
5am Mostly Cloudy 59º 20% SSW 9 mph 91%
6am Mostly Cloudy 59º 21% SW 9 mph 91%
7am Mostly Cloudy 59º 20% SW 9 mph 92%
8am Mostly Cloudy 60º 19% SSW 9 mph 90%
9am Mostly Cloudy 61º 23% SSW 9 mph 88%
10am Cloudy 62º 16% SSW 10 mph 85%
11am Mostly Cloudy 63º 12% SW 11 mph 82%
12pm Mostly Cloudy 65º 9% SW 12 mph 79%
1pm Partly Cloudy 66º 9% SW 14 mph 77%
2pm Partly Cloudy 66º 10% SW 15 mph 75%
3pm Partly Cloudy 67º 6% SW 16 mph 74%
4pm Partly Cloudy 66º 5% SW 16 mph 74%
5pm Partly Cloudy 65º 5% SW 15 mph 75%
6pm Partly Cloudy 64º 7% SW 16 mph 77%
7pm Partly Cloudy 63º 13% SW 15 mph 81%
8pm Mostly Cloudy 60º 15% SW 14 mph 87%
9pm Mostly Cloudy 60º 16% SW 12 mph 90%
10pm Cloudy 59º 16% SW 11 mph 92%
11pm Mostly Cloudy 59º 23% SW 10 mph 92%
Wed
Aug 12 		Cloudy
View Hourly 		68º / 58º 17% SW 16 mph 81%
12am Mostly Cloudy 59º 16% SW 10 mph 93%
1am Mostly Cloudy 58º 17% SW 9 mph 93%
2am Cloudy 58º 17% SW 9 mph 93%
3am Cloudy 59º 18% SSW 9 mph 92%
4am Cloudy 59º 17% SSW 9 mph 92%
5am Cloudy 59º 18% SSW 9 mph 91%
6am Cloudy 59º 15% SSW 9 mph 92%
Thu
Aug 13 		AM Clouds/PM Sun 68º / 58º 8% SW 16 mph 78%
Fri
Aug 14 		AM Clouds/PM Sun 69º / 58º 9% SW 15 mph 76%
Sat
Aug 15 		AM Clouds/PM Sun 69º / 57º 7% WSW 14 mph 77%
Sun
Aug 16 		AM Clouds/PM Sun 69º / 57º 7% WSW 15 mph 76%
Mon
Aug 17 		Partly Cloudy 70º / 58º 7% W 15 mph 76%

Weather Radar for Alcatraz Island, CA See Radar

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* Playback displays weather for the past 6 hours.

NOAA Weather Marine Forecast for Alcatraz Island, CA

Monday
High : 61ºF
WSW wind 14 to 21 kt, with gusts as high as 30 kt. Partly sunny.
Monday Night
Low : 58ºF
SW wind 10 to 19 kt, with gusts as high as 27 kt. Mostly cloudy.
Tuesday
High : 61ºF
SW wind 9 to 16 kt. Mostly cloudy, then gradually becoming sunny.
Tuesday Night
Low : 58ºF
SW wind 10 to 15 kt. Mostly cloudy.
Wednesday
High : 61ºF
SSW wind 10 to 16 kt. Partly sunny.
Wednesday Night
Low : 59ºF
SW wind 13 to 17 kt. Mostly cloudy.
Thursday
High : 60ºF
SSW wind 11 to 18 kt. Partly sunny.
Thursday Night
Low : 59ºF
SW wind 10 to 17 kt. Mostly cloudy.
Friday
High : 61ºF
SW wind 8 to 16 kt. Partly sunny.

NOAA Buoy Data Near Alcatraz Island, CA See Map

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    Wind Speed Forecast for Alcatraz Island, CA

    MondayTuesdayWednesday
    Wind Speed (MPH) 71317151199111615109
    2pm6pm10pm2am6am10am2pm6pm10pm2am6am10am
    MPH 71317151199111615109
    DIR SWSWSWSWSWSWSWSWSWSWSWSSW

    Current Weather Conditions In Alcatraz Island, CA

    As Of: 20 minutes ago

    • 58ºF
    • 57ºF
    • 7mph
    • 0º (SW)
    • 7mph
    • Mostly Cloudy
    • 5mi
    • 29.88"
    • 91%
    • 0ºF

    The weather right now in Alcatraz Island, CA is Mostly Cloudy. The current temperature is 58°F, and the expected high and low for today, Monday, August 10, 2026, are 66° high temperature and 57°F low temperature. The wind is currently blowing at 7 miles per hour, and coming from the Southwest. The wind is gusting to 7 mph. With the wind and the atmosphere the temperature feels like 57° Fahrenheit. Expected precipitation is 15 percent, with current humidity at 91 percent, and air pressure at 29.88 in. Visibility is 5 nautical miles. There are 2 current weather alert(s).

    Weather Alerts
    Small Craft Advisory - 2:48am Mon Aug 10 2026

    ...SMALL CRAFT ADVISORY NOW IN EFFECT UNTIL 9 PM PDT THIS EVENING...

    WHAT: Southwest winds 10 to 20 kt with gusts up to 30 kt and
    choppy waters.

    WHERE: San Pablo Bay, Suisun Bay, the West Delta and the San
    Francisco Bay north of the Bay Bridge.

    WHEN: Until 9 PM PDT this evening.

    IMPACTS: Conditions will be hazardous to small craft.

    PRECAUTIONARY / PREPAREDNESS ACTIONS:

    Inexperienced mariners, especially those operating smaller
    vessels, should avoid navigating in hazardous conditions.

    &&

    Coastal Flood Advisory - 9:43pm Sun Aug 9 2026

    ...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 2 AM PDT THURSDAY...

    WHAT: Up to 1.6 ft of inundation above ground level is
    possible in low-lying areas near shorelines and tidal
    waterways.

    WHERE: Bayshore locations along the San Francisco Bay, San
    Pablo Bay, and Monterey Bay.

    WHEN: Until 2 AM PDT Thursday.

    IMPACTS: Flooding of lots, parks, and roads with only
    isolated road closures expected.

    ADDITIONAL DETAILS: At the San Francisco tidal gauge, high tide
    is expected to be 1.6 ft above normal (7.46 ft MLLW) at 10:01 PM
    Monday 8/10, 1.6 ft above normal (7.44 ft MLLW) at 10:57 PM
    Tuesday 8/11, and 1.4 ft above normal (7.24 ft MLLW) at 11:49 PM
    Wednesday 8/12. These predictions include both astronomical
    tides and roughly 3-6 inches of additional water mainly from a
    combination of thermal expansion and accumulated sea level rise
    since the tidal datum was established (1983-2001). High tide
    varies up to 90 minutes earlier or later along the Pacific Coast
    and through the San Francisco Bay, respectively.

    PRECAUTIONARY / PREPAREDNESS ACTIONS:

    If travel is required, allow extra time as some roads may be
    closed. Do not drive around barricades or through water of
    unknown depth. Take the necessary actions to protect flood-prone
    property.

    &&