California Just Recorded Its Driest Year In Nearly A Century

Water officials warned that the state's "climate is transitioning to a warmer setting."

California, which has been plagued by some of its worst droughts and wildfires in recent years, just recorded its driest year in nearly a century, according to data that state water officials released earlier this month.

The 2021 water year ― a period that ran from Oct. 1, 2020, to Sept. 30, 2021 ― marked the least rainfall since 1924 and was the second driest year since the state started tracking the metric 125 years ago.

“[E]xtreme conditions that once were rare are occurring with increased frequency,” the state’s Department of Water Resources said. “California’s climate is transitioning to a warmer setting in which historical relationships among temperature, precipitation, and runoff are changing.”

Several areas ― including San Francisco, Los Angeles and Sacramento ― experienced less than half of their average annual rainfall, the report found. Overall, California was one of the driest states in the western U.S. last year.

Rainfall across the West for the 2021 water year.
Rainfall across the West for the 2021 water year.
California Department of Water Resources

The 2020 water year was quite dry as well, and had the fifth lowest rainfall on record.

“This two-year dry period continues the theme of aridity California has been experiencing in the 21st century, including the three-year drought of 2007-2009 and the five-year one of 2012-2016,” the department said. A very wet 2017 water year offered a brief reprieve, but drought began returning in 2018.

Snowpack in the Sierra-Cascades mountain area in the spring was 60% of average, the department said, indicating potentially grim water supply conditions going forward. Fifty of California’s 58 counties are currently under emergency drought proclamations, and residents have been asked to reduce water consumption.

The summer months were especially arid and marked the driest July, August and September since the state started keeping such records around the turn of the 20th century.

The continued dryness adds literal fuel to California’s greatest existential threat: massive, record-breaking wildfires. Some of the worst blazes in state history have ripped across California in recent years, burning down entire communities and creating hospitable conditions for other natural disasters.

The 2021 water year included the Dixie fire, which started in July and is still burning in some areas. It is the largest single wildfire in state history and the second largest when stacked up against wildfire complexes made up of multiple blazes.

Meteorologists have warned the fire risk may be elevated by a strong season of Santa Ana winds, a weather phenomenon with hot, gusty winds that typically descend from October through March.