Meteorologists tell us that warmer air holds more moisture than cooler air. As temperatures rise over land and sea, more water evaporates into the atmosphere. This increases the amount of water vapor that can be released when the hot air compresses or cools. More moisture in the air, combined with changes in large-scale weather patterns like an El Nino event, can lead to more rain, snow, and heavy downpours.
Globally, annual average precipitation has increased by 2% (0.09 inches per decade) since 1900. The U.S. has seen larger changes in average precipitation, with a 5% (0.15 inches per decade) increase since 1900(1).
Did you know the year 2015 was the third wettest year on record for the continental United States? Rainfall totals were 4.5” above the 20th century average(2).
Although the precipitation trend is increasing globally, patterns of precipitation vary widely by region. In the U.S., the Northeast and Midwest regions have experienced wetter weather patterns since 1991, while the Southwest has struggled with severe drought(1).