Climate Shift Index Alert•July 7, 2025
Understanding the climate connection with the devastating Texas floods
Climate Central held a briefing on July 8 where our panel of climate scientists and meteorologists broke down the meteorology behind the Texas flood disaster, how climate change is fueling more intense rainfall and flooding, and the critical importance of local officials, the National Weather Service, NOAA, and FEMA in forecasting, preparedness, and response. |
Devastating flash floods across the Hill Country in central Texas on July 4 to 7, 2025 left a trail of destruction claiming over 80 lives with more still unaccounted for. The cause? Slow-moving thunderstorms that dropped 10 to 20 inches of rain in just a few hours, over an area known as "Flash Flood Alley” in central Texas. A lot of that water funneled into the Guadalupe River, where water rose over 20 feet in just a few hours early Friday morning.
Large amounts of moisture in the air fueled the storm that moved slowly — dumping what is estimated to be more than 100 billion gallons of water, more than the daily flow over Niagara Falls — creating conditions for fatal flash floods in the early morning hours of the 4th of July holiday when it was easy to catch people by surprise.
As climate change drives more extreme weather, events like this are becoming increasingly common. We’ve long known that places like this are vulnerable, and in a warming world, unnatural disasters are only becoming more likely.
Climate influence
These floods were fueled by an intense, moisture-heavy storm, which is made more likely and powerful in a warmer climate.
In a warming climate, the atmosphere can hold more moisture, leading to heavier and more intense rainfall. Instead of uniform, widespread rain, we’re seeing more localized, extreme downpours as storms tap into unusually high moisture levels.
At the time of the floods, Kerr County was experiencing extreme to exceptional drought conditions, highlighting how dry soils can quickly transition to dangerous flooding when intense rainfall occurs. Drought conditions are exacerbated by climate change.
Though it is difficult to directly attribute specific rain events to climate change, we know that storms like these are becoming more likely as climate change worsens.