The American Red Cross will hold a blood drive today through Saturday.
Summer is usually the worst time of the year for the area's supply, but this year is an exception.
"We are above where we need to be," Red Cross spokeswoman Katrina Richardson said. "We oftentimes in the summer bring blood in from other parts of the country because we don't collect enough locally."
About one-third of the area supply is imported, Richardson said. The purpose of the drive is to maintain the current high quantity, she added.
Radio station KLOS-FM will host the drive for the 15th year at sites throughout Los Angeles and Orange counties.
The drive will open at 6:30 a.m. today in Los Angeles, with collection sites also planned in Santa Ana, Long Beach, Santa Monica and Claremont.