SAN FRANCISCO — California residents are celebrating the sunny Memorial Day weekend more upbeat than they have been for any other holiday since the pandemic began, thanks to dramatically lower virus case rates and increasing vaccinations.

About 90% of the state population is in the lower two of four tiers that restrict business operations and other activities. By June 15, California will end the tier system and relax social distancing and masking rules.

Many tourist attractions say they’re already swamped. One business owner in wine country says she’s had to limit the number of nights her restaurants and bar are open because she can’t find enough people to work.