Map: US increase in the top 1 percent of daily rainfall events (1950-2016)

Heavier precipitation is a signature of climate change. For every 1°F of temperature increase, the atmosphere can effectively hold 4 percent more water vapor. So as the world warms from the increase in greenhouse gases, the amount of evaporation also increases from oceans, lakes, rivers, and soils. The extra water vapor is available to produce additional rain and snow, creating an environment ripe for heavy precipitation events which is exactly what we are seeing in the numbers. This week’s analysis, an update from our 2015 Climate Matters, shows an increase in the top 1 percent of daily rainfall events across the vast majority of states in the U.S.