Rainbow over the UC Davis campus
Rainbow over the UC Davis campus. Photo credit: Maddie Payne / AGGIE

October storm sets new records for single-day rainfall after years-long dry spell

Climate change and drought concerns persist despite record-breaking precipitation

On Oct. 24, Sacramento received a total of 5.44 inches of rain. This marks the largest 24-hour precipitation in over 100 years, breaking the previous record established in 1880. The weekend of rain also provided the North Sierra half the amount of rain in just one weekend than the entire region has received over the entire last year.

While it is tempting to view the rainfall as a turning point in California’s ongoing drought emergency, it follows an extremely dry period beginning in 2019. Associate professor of climate change impacts, Erwan Monier, warned that we should not expect the rain to continue into the winter season.

“We expect these coming months/year to continue to be drier than usual—the 2019-2021 period has been extremely dry,” Monier said via email. “The recent precipitation is an anomaly and should not be seen as the beginning of a wet year.”

The rainfall on the weekend of Oct. 23 was an extreme event, but one that we should expect to see more of. With climate change, extreme events such as these will become increasingly common in the coming years, according to Monier.

“We don’t necessarily expect substantial changes in the total amount of annual precipitation in California, but we expect the rainy season to shorten, meaning we expect more intense precipitation when it falls,” Monier said via email. “Similarly, we expect a longer dry season, meaning Fall and Spring will experience less precipitation.”

In addition to more extreme floods and droughts, California should expect increased heat waves, major snowpack loss and increases in wildfire severity. Climate change has created conditions in which environmental events tend to become more extreme, according to Monier.

“Essentially, we expect increases in both flooding and droughts, however counterintuitive it may be,” Monier said via email. “Think: when it rains it pours, and when it’s dry it’s extremely dry. Climate change has been and will continue to intensify these two extremes.”


Like Monier, faculty professor and cooperative extension specialist in water resources, Samuel Sandoval Solis, stressed that the recent rain does not mean the end of California’s water problems.

“This rain is not breaking the drought,” Sandoval Solis said. “It is a good start and it replenished the deficit in moisture in Northern California but we are by no means in a position to replenish two years of below normal conditions.”


Source: The California Aggie

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