That’s because a warmer atmosphere can hold more moisture. That extra water vapor means storms can drop more rain than in the past. Today, the heaviest rainstorms in Texas drop about 20% more water than they did in the late 1950s, when the planet was significantly cooler, according to the National Climate Assessment. And extreme rain in Texas is expected to get much more frequent in the coming decade, as the climate warms even more, according to a 2024 report by the Texas state climatologist.