Climate change worsened by human behavior made 2025 one of the hottest years ever recorded. Also, the three-year warming average has crossed for the first time the threshold of 1.5 degrees Celsius – or 2.7 degrees Fahrenheit – since preindustrial times that was set in the 2015 Paris Agreement. The analysis from World Weather Attribution researchers comes as once again, people around the world were slammed by drastic, dangerous extremes brought on by a warming planet. Extreme-weather events kill thousands of people and cost billions of dollars in damage annually. Climate scientists identified 157 extreme-weather events as most severe in 2025.