This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

California is entering the holiday season with an uncertain outlook. Optimistically, new weekly coronavirus cases have become stable statewide; the vaccination rate is higher than in many other states, and there are few signs right now of a big winter surge.

But the deteriorating conditions in Colorado offer a cautionary tale of how things can go south quickly, even in a state where many residents are vaccinated.

Colorado “may be a precursor to what we could see ultimately here in California as things get cooler for us,” UCLA epidemiologist Dr. Robert Kim-Farley said. Chillier weather hits Colorado earlier than California, sending people indoors, “which leads to higher potential for transmission of COVID.”

In Colorado, 62.8% of all residents are fully vaccinated, almost identical to California’s 62.7%, according to the U.S. Centers for Disease Control and Prevention. But the differences in weekly case rates are stark: CDC data show California currently has the 10th lowest out of all states, and Colorado has the eighth highest.

Read the full story on LATimes.com.