San Ramon Warnings, Watches and Advisories

When a severe thunderstorm warning is issued, the storm may produce damaging winds, large hail, dangerous lightning, and heavy rain. In some cases, heavy rainfall produced by a severe storm can also lead to flash flooding. Do not drive vehicles through flooded areas. The water depth or fast flowing water/mud/debris from a flash flood will make road conditions unsafe. Do not rely soley on data presented here or other third-party websites - always check your official national and local weather service agency website, socials, radio and/or TV stations for making critical decisions related to weather events.

Please carefully read each posted Warning and Alert as it relates to the area(s) being affected. We may provide a wider range of issued severe weather warnings for surrounding cities and counties, so some alerts may not directly impact this location. This is done to help with preparing for severe weather that may overlap or be heading towards San Ramon.

Use the Radar Maps link provided to understand the trajectory of a storm.

Beach Hazards Statement issued September 4 at 9:41PM PDT until September 7 at 11:00PM PDT by NWS Eureka CA

* WHAT...Increased threat of sneaker waves expected. * WHERE...Southwestern Humboldt and Coastal Mendocino Counties. * WHEN...From 5 AM PDT Saturday through Monday evening. . * IMPACTS...Large, unexpected waves can sweep across the beach without warning, sweeping people into the sea from rocks, jetties, and beaches. These sneaker waves can also move large objects such as logs, crushing anyone caught underneath.

High Surf Advisory issued September 4 at 9:24PM PDT until September 8 at 11:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...For the Coastal Flood Advisory, moderate coastal flooding expected. For the High Surf Advisory, large breaking waves of 5 to 8 feet with local sets to 10 feet and dangerous and potentially life threatening rip currents, largest on south- facing shores. * WHERE...Catalina and Santa Barbara Islands, Ventura County Beaches, Malibu Coast and Los Angeles County Beaches. * WHEN...From 6 AM Saturday to 11 PM PDT Tuesday. * IMPACTS...There is an increased risk for ocean drowning. Rip currents will be widespread and very strong, potentially pulling swimmers and surfers out to sea. Large breaking waves can cause injury, wash people off beaches and rocks, and capsize small boats near shore. Enhanced beach erosion will occur. Flooding of sea water is likely, around the time of high tide, over vulnerable low-lying coastal areas such as parking lots, beaches, and walkways. Areas most susceptible to coastal flooding will include Avalon, Long Beach (Alamitos Peninsula), and Oxnard to Malibu (including Point Mugu). * ADDITIONAL DETAILS...High tides at 6.3 feet will occur around 5pm on Saturday, 6.7 feet at 6pm on Sunday, 7 feet at 7pm on Monday, and 7.2 feet at 8pm on Tuesday.

Beach Hazards Statement issued September 4 at 9:24PM PDT until September 8 at 11:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Dangerous and potentially life threatening rip currents and breaking waves due to elevated surf expected. * WHERE...San Luis Obispo County Beaches, Santa Barbara County Central Coast Beaches, Santa Barbara County Southwestern Coast and Santa Barbara County Southeastern Coast. * WHEN...From 6 AM PDT Saturday through Tuesday evening. * IMPACTS...There is an increased risk of ocean drowning. Rip currents will be widespread and very strong, potentially pulling swimmers and surfers out to sea. Waves can wash people off beaches and rocks. Pooling of sea water is possible around high tide at beach areas that is uncommon with normal tidal ranges. Enhanced beach erosion is also possible. No significant damage is expected. * ADDITIONAL DETAILS...High tides will occur around 6.1 feet at 5pm on Saturday, 6.3 feet at 630pm on Sunday, 6.5 feet at 730pm on Monday, and 6.5 feet at 830pm on Tuesday.

Coastal Flood Advisory issued September 4 at 9:24PM PDT until September 8 at 11:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...For the Coastal Flood Advisory, moderate coastal flooding expected. For the High Surf Advisory, large breaking waves of 5 to 8 feet with local sets to 10 feet and dangerous and potentially life threatening rip currents, largest on south- facing shores. * WHERE...Catalina and Santa Barbara Islands, Ventura County Beaches, Malibu Coast and Los Angeles County Beaches. * WHEN...From 6 AM Saturday to 11 PM PDT Tuesday. * IMPACTS...There is an increased risk for ocean drowning. Rip currents will be widespread and very strong, potentially pulling swimmers and surfers out to sea. Large breaking waves can cause injury, wash people off beaches and rocks, and capsize small boats near shore. Enhanced beach erosion will occur. Flooding of sea water is likely, around the time of high tide, over vulnerable low-lying coastal areas such as parking lots, beaches, and walkways. Areas most susceptible to coastal flooding will include Avalon, Long Beach (Alamitos Peninsula), and Oxnard to Malibu (including Point Mugu). * ADDITIONAL DETAILS...High tides at 6.3 feet will occur around 5pm on Saturday, 6.7 feet at 6pm on Sunday, 7 feet at 7pm on Monday, and 7.2 feet at 8pm on Tuesday.

Beach Hazards Statement issued September 4 at 9:03PM PDT until September 7 at 11:00PM PDT by NWS San Francisco CA

* WHAT...Increased risk of sneaker waves and strong rip currents due to incoming long period southerly swell associated with tropical activity in the Eastern Pacific Ocean. Breaking waves to around 10 feet expected. * WHERE...Pacific Coast beaches. * WHEN...Through 11 PM PDT Monday. * IMPACTS...Dangerous conditions are forecast along the shoreline. Hazards include sneaker waves, strong rip currents, and large breaking waves.

Coastal Flood Advisory issued September 4 at 1:23PM PDT until September 8 at 11:00PM PDT by NWS San Diego CA

* WHAT...Large breaking waves of 6 to 10 feet for south and southwestern-facing beaches and 4 to 7 feet for west-facing beaches. Strong and dangerous rip and longshore currents. Minor coastal flooding from a combination of high surf and high astronomical tides. * WHERE...San Diego County coastal areas and Orange County coastal areas. * WHEN...From 6 AM Saturday morning to 11 PM PDT Tuesday. * IMPACTS...Flooding of lots, parks, and roads with only isolated road closures expected. Dangerous swimming and surfing conditions and beach erosion. * ADDITIONAL DETAILS...Predicted tides for La Jolla, CA: Sat, Sep 5 2026: 6.0 feet at 4:48 PM PDT Sun, Sep 6 2026: 6.3 feet at 6:03 PM PDT Mon, Sep 7 2026: 6.7 feet at 7:03 PM PDT Tue, Sep 8 2026: 6.8 feet at 7:54 PM PDT

High Surf Advisory issued September 4 at 1:23PM PDT until September 8 at 11:00PM PDT by NWS San Diego CA

* WHAT...Large breaking waves of 6 to 10 feet for south and southwestern-facing beaches and 4 to 7 feet for west-facing beaches. Strong and dangerous rip and longshore currents. Minor coastal flooding from a combination of high surf and high astronomical tides. * WHERE...San Diego County coastal areas and Orange County coastal areas. * WHEN...From 6 AM Saturday morning to 11 PM PDT Tuesday. * IMPACTS...Flooding of lots, parks, and roads with only isolated road closures expected. Dangerous swimming and surfing conditions and beach erosion. * ADDITIONAL DETAILS...Predicted tides for La Jolla, CA: Sat, Sep 5 2026: 6.0 feet at 4:48 PM PDT Sun, Sep 6 2026: 6.3 feet at 6:03 PM PDT Mon, Sep 7 2026: 6.7 feet at 7:03 PM PDT Tue, Sep 8 2026: 6.8 feet at 7:54 PM PDT