Average annual precipitation

Historically, the annual average rainfall in the United States has trended slightly upwards. Climate change has caused more extreme weather to occur, which includes heightened levels of increased precipitation. This has led to a slow increase in the average annual rainfall. Since 1980, annual rainfall has averaged around 30.0 inches. The two years that saw the most rain were 1983, with 34.76 inches and most recently, 2018, with 34.65 inches.

The Pacific Northwest contributes more than any other region, with rainfall averaging six to seven times the national average. The Deep South, at 60.0 to 70.0 inches per year, is the other region averaging significantly more than the national average. The Midwest, Great Plains, Northeast and Atlantic Coast all receive about the national average, while the Rocky Mountains and Southwest receive significantly less. However recent strong bouts of droughts have impacted the North America region, especially in 2020 when the annual average precipitation fell by 12.8% While 2021 brought upon a slight recovery of rain, growing 0.1%, 2022 was another dry season for the United States region, with average precipitation rates declining 6.4% But 2023 represented a more noticeable boost in precipitation numbers with it going up 3.6% in the year. Even as droughts still have remained present in certain parts of the United States, the year noticeably left certain states with more rain in the year which did help push up precipitation rates from last year for rainfall levels when such areas did not experience as much rain as it did with the following year. But factors like the warmer temperatures only add pressures for drought levels for areas that are not on the path of storms that did hit parts of the country more frequently in comparison which has pressured such rates from going up to levels sustained in past years rather it has kept rates at more lower rates but not lower from the year before. In 2024, heightened hurricane activity led to a significant boost in precipitation levels, up by 6.9%. These climatic changes are expected to influence rainfall patterns moving forward, resulting in fluctuations between heavy rainfall and periods of drought. The increased risk of wildfires remains a concern, as evidenced by the recent events in Southern California in early 2025.