… According to data from the Scripps Institution of Oceanography, 56 atmospheric rivers impacted the western U.S. during late 2024 and early 2025, with the majority affecting Oregon and Northern California. … Forecasters note that Northern California typically experiences about six strong atmospheric rivers every year, but by April 1, that number had already reached nine. This increase in storm system intensity and frequency led to above-normal precipitation levels, particularly in critical watershed zones, but, in contrast, Southern California saw very few significant storms, receiving only a handful of weak systems. As a result, precipitation totals in Southern California dropped to 70% or less of average levels through early March, setting the stage for an increasingly dangerous fire season.