Scientists have been able to compare the development of the current climate phenomenon El Niño with its strongest historical counterparts thanks to a 35-year archive of satellite altimetry data. This technology makes it possible to measure sea surface height, which is an important indicator of heat distribution in the ocean and the intensity of El Niño. El Niño is a natural climate cycle associated with warming of surface waters in the central and eastern parts of the Pacific Ocean. The phenomenon has a significant impact on weather conditions worldwide, causing droughts in some regions and excessive rainfall in others, and also affects temperature records and marine ecosystems. Long-term satellite observations give scientists a unique opportunity to track the dynamics of sea level rise and temperature anomalies in real time, comparing them with data on past powerful El Niño episodes, including events from the late 1990s and mid-2010s. Such comparison helps specialists more accurately classify the strength of the current phenomenon and build forecasts regarding its further development. Understanding the scale of the current El Niño has practical significance for weather forecasting, agricultural planning, water resource management, and preparation for possible extreme weather events in different parts of the world. The accumulated array of satellite data continues to serve as a valuable tool for climate research.