The Gulf, which borders Texas, has become significantly warmer in recent years due to climate change, Swain explained. This results in a very warm body of water that produces a lot of evaporation, releasing more tropical moisture into the air than seen historically.

Together, they dropped more than four months’ worth of rain—at least 1.8 trillion gallons, roughly enough to cover the entire state of Texas in four inches of water—in just four hours. Much of this rain fell over a picturesque stretch of the Texas Hill Country dotted by summer camps,