Watch the ocean change as El Niño grows through the lens of NASA’s satellites.
How El Niño Reaches the Coast
Conditions in the Pacific Ocean are shaping the way communities across the globe will experience weather patterns and coastal flooding in the coming months. El Niño is the name given to a global phenomenon wherein weakened surface winds across the Pacific position maximum sea surface temperatures in the eastern and central equatorial Pacific. A strong El Niño has been building for the past 6 months. Sea surface temperature patterns reflect the movement of underlying warm water masses as they traverse the Pacific from west to east along the equator, bombarding the coastal barrier and traveling northward along the west coasts of the Americas. The warm water bulges in the upper ocean raise the height of the ocean surface as they travel, creating elevated risk of coastal flooding for many communities.
At the Shore
Top: a cross-section of the shoreline at the beach, with the day’s highest water, split between the contribution from the normal sea level, El Niño, and the tide; waves are not included. The dotted line is the minor flood level at the location, set by NOAA. The chart below gives each day’s highest water since March. Future dates use NOAA’s tide forecast, with the El Niño part held at its latest value. Pick a site to switch beaches.
Water Level on the Beach (m)
Contributors to Water Level
Highest Water Each Day
Higher Tides Along California
Along the coast of southern to central California, tides have been higher than normal due to El Niño’s increased baseline sea level. Additionally, storm and wave driven increases in water level are more impactful, as demonstrated by the recent impacts of Tropical Storm Rachel.
Sea Level Along the Coast Since 1950
Averaging water levels across stretches of coast sheds light on the magnitude of this El Niño compared to previous ones. For example, the current sea level averaged over California is already higher than at this point in the 1997-1998 El Niño, and may continue to increase as the season progresses. King tides and continued storm activity will breed conditions ripe for coastal hazards such as flooding, coastal cliff instability, and beach erosion.
These plots show the monthly average sea level along the coast from historical NOAA tide gauge data. Buttons choose the stretch of coast for averaging.
Daily sea level compared with normal (its 1993–2025 average, trend and seasons).
Days each month with at least minor flooding.
Sea level each year from January to the following June.
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