Global Sea Level Rise in 2025 Sees Slower Increase

The global mean sea level increased by 0.03 inches (0.08 centimeters) in 2025, according to a NASA analysis. This rate of increase was lower than the 0.23 inches (0.59 centimeters) recorded in 2024 and fell below the long-term annual average of 0.17 inches (0.44 centimeters) observed since the early 1990s.

Impact of La Niña

The reduced rate of sea level rise in 2025 was largely influenced by mild La Niña conditions that persisted for most of the year. La Niña, a phase of the El Niño-Southern Oscillation (ENSO) cycle, typically cools the eastern Pacific Ocean and often leads to increased rainfall in equatorial South America, including the Amazon River basin.

This phenomenon resulted in a temporary shift of a significant amount of water from the oceans to land due to heavier-than-normal rainfall in the Amazon basin. This land-based water storage offset the rise in sea levels caused by the melting of glaciers and ice sheets, as well as the thermal expansion of warming ocean waters.

"This temporary cycle is short-lived, and the stored water will eventually return to the oceans, likely leading to a resumption of rapid sea level rise."
— Josh Willis, Sea Level Researcher at NASA's Jet Propulsion Laboratory

Measurement and Analysis

Scientists utilized data from several satellite missions and oceanographic programs to determine the global mean sea level and its contributing factors in 2025:

• Sentinel-6 Michael Freilich: The primary reference satellite for sea level measurements.
• Gravity Recovery and Climate Experiment Follow-On (GRACE-FO): Tracked water movement by measuring changes in Earth's gravity, indicating water shifted to the Amazon basin.
• Argo Program: Used seaborne probes to measure ocean temperatures and salinity, revealing record ocean warming in 2025.

Despite continued ice loss from glaciers and ice sheets adding water to oceans, the La Niña-induced rainfall caused an opposing effect, resulting in the lower-than-average sea level rise for the year.

Long-Term Trends

Since 1993, satellite data indicates that the average global sea level has risen by 4 inches (10 centimeters). The overall trend shows that the annual rate of sea level rise has more than doubled over the past three decades. This continuous satellite monitoring, spanning over 30 years from missions like TOPEX/Poseidon to Sentinel-6 Michael Freilich and its upcoming twin Sentinel-6B, provides crucial data for flood predictions and coastal resilience efforts.

"Satellite monitoring is incredibly important for communities globally to anticipate risks and enhance resilience as sea levels continue to rise."
— Nadya Shiffer, Head of Physical Oceanography Programs at NASA Headquarters