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◒ SoCal Tide Watch

Understanding Southern California’s high water

Why SoCal Tide Watch was built, what can raise the ocean above the tide tables, and where to learn more.

Background reviewed . This page explains context, not live conditions.

Why this was built

SoCal Tide Watch was built for people living near Southern California’s coast who want to understand high water, whether out of curiosity or concern for a low-lying home, street or neighborhood. Recent flooding in Newport Beach, Laguna Beach and Sunset Beach made that need especially clear.

The question behind the dashboard is simple: how far is the ocean running above or below the tide tables, and what would the next high tides look like if that extra water stayed the same? Los Angeles and Long Beach NOAA gauges provide regional context. They do not predict flooding at an individual property, beach or city.

What happened in October 2026

In its November 4 report on California’s record water levels, NOAA reported all-time station records at San Diego, La Jolla, Los Angeles and Santa Barbara during October 24–30, 2026. Santa Monica recorded its second-highest level. These are records at named gauges, not a claim that every Southern California beach reached a new record.

Newport Beach’s October 30 city bulletin described October 27’s water level as the highest in city records dating to the 1920s. The bulletin does not state a vertical datum, so its reported height is not used as a direct comparison with the dashboard’s NOAA measurements.

Laguna Beach has a different, locally important example: October 9 reporting described high tide and surf flooding Coast Highway near Broadway, with temporary road closures. ABC7 also covered the high surf and flooding. Those reports are not evidence of a Laguna Beach water-level record, and they are not current road-status notices.

In Sunset Beach, ABC7’s October 27 report documented neighborhood and property flooding, cleanup efforts and a Pacific Coast Highway closure. Together, these local accounts show why residents want more than a tide-table time: the height of the surrounding water and surf conditions matter too.

King tides start from a changing baseline

Very high tides have always been part of coastal life. “King tide” is an informal name for an exceptionally high tide, not a new kind of event. The Moon and Sun drive the regular tidal cycle; their alignment, the Moon’s distance from Earth and the time of year help determine how high a tide becomes. These astronomical patterns are the predictable part shown in tide tables.

What changes the impact is the level from which those tides start. Long-term sea-level rise raises that baseline, allowing high water to reach flood thresholds more often. Winds, currents and other shorter-term ocean changes can raise or lower the water further. At exposed beaches, surf also matters. A familiar high tide can therefore have unfamiliar consequences, especially in low-lying places.

What is a Kelvin wave?

A Kelvin wave is a broad signal moving through the ocean that can change sea level and the depth of warm water. It is different from a breaking wave at the beach. During El Niño, the usual westward-blowing tropical Pacific trade winds can weaken or briefly reverse. Bursts of west-to-east wind can launch equatorial Kelvin waves eastward toward the Americas. When the signal reaches the eastern Pacific, part of it can continue along the coast toward higher latitudes. Earth’s rotation helps guide these waves along the equator or a coast. The result can be a regional rise in water level that makes an already high astronomical tide reach higher.

The recent context is a sequence of waves, not one isolated wave with a single arrival date. NOAA’s account of El Niño’s arrival on the West Coast documents initial arrivals in May and June 2026. Its October 6 explainer described another wave moving up the coast, with additional waves behind it. A historical view of coastal waves during the 1997–98 El Niño shows that this is a recurring ocean process. For October 2026, NOAA identified astronomical tides, El Niño-driven Kelvin waves and a marine heatwave as contributors to the high water. Those accounts do not assign a separate number of inches to each cause at Newport Beach, Laguna Beach or an individual property.

How to use SoCal Tide Watch

The dashboard’s main number is the latest 24-hour average difference between observed water level and the astronomical tide prediction at the selected station. The future comparisons add that average to a future predicted high tide, holding the residual constant. They are what-ifs, not forecasts: the extra water can change before those dates arrive.

The residual combines effects that the station observations alone cannot separate. SoCal Tide Watch does not label the entire difference as a Kelvin wave or add a separate sea-level-rise amount on top of it. It also does not turn a regional gauge height into a local flood depth.

For decisions about immediate safety, road access or protecting property, use National Weather Service advisories and your city’s current notices. This explainer and the dashboard are background information, not emergency guidance.

Return to the tide dashboard →

Science and local reporting

Start with the science

  • What is a King Tide?NOAA Ocean Service · updated September 23, 2026. A plain-language explanation of exceptionally high astronomical tides.
  • What is high tide flooding?NOAA Ocean Service · updated September 23, 2026. How rising relative sea level and other conditions can produce flooding without a major storm.
  • What is a Kelvin wave?NOAA Ocean Service · updated October 15, 2026. Equatorial and coastal propagation, and why several waves may arrive over time.
  • Ocean Indicators We’re Tracking for El Niño’s Arrival on the West CoastNOAA Fisheries · September 3, 2026; updated October 2. The 2026 sequence and its early May/June signals. The article’s historical map depicts 1997–98, not current observations.
  • Kelvin Waves, ExplainedNOAA Fisheries · October 6, 2026. How temporary elevated water can amplify high tides and storm surges.
  • Coastal Trapped WavesDillon J. Amaya · update labeled November 6, 2026. Tracking and a separately identified 1997–98 historical animation.

Read the local accounts

Check official conditions

  • National Weather Service: San DiegoOfficial forecasts and advisories for Orange County and San Diego County. Check the issue time and affected area.
  • NOAA Coastal Inundation DashboardStation observations, predictions, historical peaks and flood thresholds. Its default datum is MHHW; SoCal Tide Watch uses MLLW. Use matching datums before comparing heights.