Sacramento temperature blanket 2024: A stormy February sees consistent cool weather

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We are officially nine squares into our temperature blanket! (If you missed our introduction to this project, you can read more here.) 

And with more data available, we’re getting a clearer sense of what average temperatures look like this year in Sacramento, and what may be the story behind them. 

Throughout the month of February, California saw the impacts of multiple atmospheric rivers. Earlier in the month, it got pretty intense; we saw some strong winds knock down local trees and tens of thousands of Sacramentans lost power. It may have reminded you of last year’s back-to-back January storms. 

But there’s a big difference. Current statewide snowpack levels were much lower this February than they were at this time last year. During the monthly survey conducted on Feb. 29, researchers at Phillips Station in Lake Tahoe saw a snow depth of about four feet. Statewide reports from the same day found snowpack levels at 80% of average. 

Last year was a different story. In February 2023, snowpack levels were nearly double the statewide average. 

So, what was the big difference between this year and last? Andy Reising, a water resources engineer with the California Department of Water Resources, said the end-of-February survey results were more promising than “when the ground was barely covered” at the start of the year. But in the last couple months, he said “we’ve had a number of warmer storms come in.” 

“What that means is where we’re normally hoping to build snowpack, rain was falling instead,” he said. 

We saw evidence of milder local temperatures in our blanket. As a reminder: Our blanket is color-coded, so different colors represent different average weekly temperatures. This month, the dominant color was blue — which means we saw average temperatures consistently in the 50s. 

Greg Pierce, the director of UCLA’s Human Right to Water Solutions Lab, said the storms we’ve seen this month brought plenty of rainfall and helped in the eternal struggle to replenish our state water supply. But warmer storms means more rainfall and less snow, which he said is “just not as beneficial.” 

“A lot of that's due to climate change and is a worrying trend to see coming to fruition,” Pierce said. 

With climate change, experts say snowpack in California’s Sierra Nevada will likely see a 48 to 65% loss from the historical April 1 average by the end of the century. Pierce said California will have to rely less and less on slow-melting snowpack as a primary water resource. That means locally ramping up the infrastructure related to other ways of holding onto water, like stormwater capture and groundwater storage.

“That’s really going to pay off, but it’s going to take decades to get there,” he told me. “We really need to invest in those to see the water supply benefits over time.”  

State officials said we’ll need more storms through March to get to our April 1 average (which is when snowpack levels usually peak). Hitting 100% of that statewide average is a good indicator that we’re well-stocked on water for the warmer months. 

Last weekend’s blizzard in the Sierra was the perfect example; in just a few short days, we saw statewide snowpack levels creep just over 100% of average. So, with some more luck and colder storms, we might just hit that April 1 average after all.