Now University of California, Davis Medical Center in Sacramento is getting ready for a surge.
"There have been 74 confirmed influenza-related deaths in California this season," said Dr. Thomas Stafford, a general practitioner with Turnure Medical Group in Rocklin.
According to Stafford, the reason the flu season has been so bad is the flu shot is not as effective.
"The flu shot is developed based off of predominant flu strains that are circulating in the southern hemisphere," Stafford told FOX40.
This year's flu strain, H3N2, changed.
"That particular strain mutated to the point where this vaccine is not particularly effective against it," Stafford said.
While the Centers for Disease Control and Prevention still recommends getting the shot, that mutation is why so many hospitals in Southern California and the Bay Area were caught off guard.
In San Bernardino County, more than 10 people have already died from the flu this year, prompting hospitals there to set up tents outside and to keep exposure to other patients to a minimum. Staff at UC Davis Medical Center tells FOX40 it has not come to that yet.
The hospital confirms it is creating a space adjacent to the emergency department for a flu treatment center, which is expected to be ready by Wednesday.
Meanwhile Stafford says this is the worse season he's seen since 2009, and those who haven't gotten sick yet need to be careful.
"I don't think you need to be so paranoid that you don't shake people's hands, but after you shake their hand, rather than going and scratching your eyes and touching your face, or eating your food, wash your hands before you do any of that kind of stuff," Stafford said.
According to the California Department of Public Health, there have been three flu-related deaths in Sacramento County, two in Yolo County and one in Placer County.