Averaged across the Lower 48, the United States has gotten modestly wetter over the past 130 years — but that national figure hides a sharp divide. The eastern half of the country is soaking up more rain than it used to, while the Southwest is drying out. This guide charts annual U.S. precipitation since 1895 and maps which states are getting wetter and which are getting drier, a shift with big consequences for farms, water supplies, and floods.
How much rain does the U.S. get?
The contiguous U.S. averages about 30 inches of precipitation a year, but that bounces around a lot from year to year — wet years and dry years can differ by ten inches or more. The chart tracks annual precipitation since 1895 against the long-term average. The single wettest and driest years stand out as sharp peaks and valleys, driven by large-scale climate patterns like El Niño and La Niña that steer storms across the country.
Is the U.S. getting wetter?
Yes — slightly, on average. The long-term trend in national precipitation drifts gently upward, consistent with a warming atmosphere, which holds more moisture and can dump it as heavier rainfall. But the national average is almost misleading, because it blends two opposite regional stories into one. The more important question isn't whether the country is wetter, but which parts of it are — and there the trends sharply diverge.
Wetter East, drier West
The map shows how each state's recent rainfall compares with its early-1900s baseline. The pattern is stark: much of the East and Midwest — states like Michigan and Arkansas — has gotten noticeably wetter, while the Southwest — Arizona and New Mexico — has gotten drier. This east-wet, west-dry split is one of the clearest regional signatures of a changing climate in the U.S., and it lines up with the long Western megadrought.
Why the shift matters
Where rain falls is as important as how much. A wetter East means more flooding, heavier downpours, and waterlogged farm fields. A drier Southwest deepens water shortages for cities and agriculture that already strain over the shrinking Colorado River. And because warming loads more moisture into the atmosphere, rainfall increasingly arrives in intense bursts rather than gentle soaks — raising flood risk even in places where the annual total hasn't changed much. The geography of rain is quietly reshaping American life.
Frequently asked questions
How much rain does the U.S. get per year?
The contiguous U.S. averages about 30 inches of precipitation a year, though it varies widely — wet and dry years can differ by ten inches or more.
Is the U.S. getting wetter?
Slightly, on average — the long-term trend drifts upward as a warming atmosphere holds more moisture. But the national average hides a sharp regional divide.
Which parts of the U.S. are getting wetter or drier?
Much of the East and Midwest has gotten wetter, while the Southwest — Arizona and New Mexico — has gotten drier, a clear east-wet, west-dry split.
What was the wettest and driest year?
Within the 1895-present record, the wettest and driest years stand out as sharp peaks and valleys, driven by climate patterns like El Niño and La Niña. The specific years are shown above.
Why does the rainfall shift matter?
A wetter East raises flood risk; a drier Southwest deepens water shortages. Warming also makes rain arrive in heavier bursts, increasing floods even where annual totals are steady.