Dozens of lightning strikes were spotted and reported south of the Bay Area Wednesday evening.
Viewer William Justo captured a stunning video of lightning and a rainbow in Hollister.
Firefighters were on alert as this type of weather can spark brush fires in an instant.
Lightning was also spotted in other parts of California.
In Los Angeles County, a woman and two dogs were killed by a lightning strike Wednesday morning as thunderstorms pounded Southern California, the Los Angeles County Sheriff's Department said.
The thunderstorms were caused by a low-pressure system off the coast pulling monsoonal moisture northward into the region, meteorologists said.
According to Chief Meteorologist Jeff Ranieri, there was a massive amount of lightning just south of Gilroy. He added it was slowly moving northwest and getting hung up on mountains.
Associated Press contributed to the report.