Station Name: SAN FRANCISCO BAY A NE SHORE ALCATRAZ ISLAND CA
Data Source: Water Data - usgc.gov

Elevation Above Sea Level: 0 feet

Nearest Address:
Alcatraz Island
San Francisco, CA 94133-1312
San Francisco County

GPS Coordinates: 37.8272222, -122.4216667

Nearby Water Temperatures

High Surf Advisory issued February 19 at 8:17AM PST until February 20 at 9:00AM PST by NWS San Francisco CA

Effective: Thu February 19, 2026, 8:17 AM
Expires: Thu February 19, 2026, 9:00 PM

* WHAT...Large breaking waves of 18 to 22 feet, with continuing increased risk of sneaker waves and strong rip currents. * WHERE...Pacific Coast beaches. * WHEN...Until 9 AM PST Friday. * IMPACTS...Dangerous swimming and surfing conditions and localized beach erosion can be expected. Sneaker waves can sweep across the shoreline without warning, pulling people into the sea from rocks, jetties and beaches. Large breaking waves can overpower swimmers resulting in significant physical injury and increase the risk of drowning.

Swimmers should remain out of the water due to dangerous surf conditions.

High Surf Advisory issued February 19 at 8:37PM PST until February 20 at 9:00AM PST by NWS San Francisco CA

Effective: Thu February 19, 2026, 8:37 PM
Expires: Fri February 20, 2026, 9:00 AM

* WHAT...Large breaking waves of 18 to 22 feet, with continuing increased risk of sneaker waves and strong rip currents. * WHERE...Pacific Coast beaches. * WHEN...Until 9 AM PST Friday. * IMPACTS...Dangerous swimming and surfing conditions and localized beach erosion can be expected. Sneaker waves can sweep across the shoreline without warning, pulling people into the sea from rocks, jetties and beaches. Large breaking waves can overpower swimmers resulting in significant physical injury and increase the risk of drowning.

Swimmers should remain out of the water due to dangerous surf conditions.

Cold Weather Advisory issued February 19 at 2:08PM PST until February 20 at 9:00AM PST by NWS San Francisco CA

Effective: Thu February 19, 2026, 2:08 PM
Expires: Thu February 19, 2026, 10:00 PM

* WHAT...Cold conditions with temperatures in the low-to-mid 30s expected. * WHERE...The Marin Hills, Western Sonoma County Hills, Northern Monterey Bay, The Santa Cruz Mountains, The Santa Clara Valley, Coastal North Bay Including Point Reyes National Seashore, San Francisco Bay Shoreline, and Northern Salinas Valley/Hollister Valley and Carmel Valley. * WHEN...From 1 AM to 9 AM PST Friday. * IMPACTS...Cold conditions will be hazardous to sensitive populations such as unhoused individuals. Prolonged exposure to the cold conditions will lead to hypothermia for people, pets, and livestock. Cold conditions may damage or kill sensitive crops, plants, and vegetation if appropriate precautions are not taken.

Ensure portable heaters are working properly and are used correctly to avoid sparking a fire indoors. Do not use generators or grills inside as carbon monoxide poisoning can result. Check with your local, city, or county officials for information on available warming centers. Be sure to dress in layers if outdoors. Make sure that pets and livestock have adequate food, unfrozen water, and warmth. Cover or tend to sensitive crops, plants, and vegetation.

Extreme Cold Warning issued February 19 at 2:08PM PST until February 20 at 9:00AM PST by NWS San Francisco CA

Effective: Thu February 19, 2026, 2:08 PM
Expires: Thu February 19, 2026, 10:00 PM

* WHAT...Very cold conditions with sub-freezing temperatures in the mid-20s to low-30s expected. * WHERE...The East Bay Hills and Valleys, Interior Monterey County and the Santa Lucia Range, Most of San Benito County and the Cholame Hills in Southeast Monterey County, North Bay Interior Mountains, North Bay Interior Valleys, Eastern Santa Clara Hills, and Southern Salinas Valley/Arroyo Seco and Lake San Antonio. * WHEN...From 1 AM to 9 AM PST Friday. * IMPACTS...Cold conditions will be hazardous to sensitive populations such as unhoused individuals. Cold conditions may damage or kill sensitive crops, plants, and vegetation if appropriate precautions are not taken. Prolonged exposure to the cold conditions will lead to hypothermia for people, pets, and livestock.

Ensure portable heaters are working properly and are used correctly to avoid sparking a fire indoors. Do not use generators or grills inside as carbon monoxide poisoning can result. Check with your local, city, or county officials for information on available warming centers. Be sure to dress in layers if outdoors. Make sure that pets and livestock have adequate food, unfrozen water, and warmth. Cover or tend to sensitive crops, plants, and vegetation.

Cold Weather Advisory issued February 19 at 9:43PM PST until February 20 at 9:00AM PST by NWS San Francisco CA

Effective: Thu February 19, 2026, 9:43 PM
Expires: Fri February 20, 2026, 9:00 AM

* WHAT...Cold conditions with temperatures in the low-to-mid 30s expected. * WHERE...The Marin Hills, Western Sonoma County Hills, Northern Monterey Bay, The Santa Cruz Mountains, The Santa Clara Valley, Coastal North Bay Including Point Reyes National Seashore, San Francisco Bay Shoreline, and Northern Salinas Valley/Hollister Valley and Carmel Valley. * WHEN...From 1 AM to 9 AM PST Friday. * IMPACTS...Cold conditions will be hazardous to sensitive populations such as unhoused individuals. Prolonged exposure to the cold conditions will lead to hypothermia for people, pets, and livestock. Cold conditions may damage or kill sensitive crops, plants, and vegetation if appropriate precautions are not taken.

Ensure portable heaters are working properly and are used correctly to avoid sparking a fire indoors. Do not use generators or grills inside as carbon monoxide poisoning can result. Check with your local, city, or county officials for information on available warming centers. Be sure to dress in layers if outdoors. Make sure that pets and livestock have adequate food, unfrozen water, and warmth. Cover or tend to sensitive crops, plants, and vegetation.