A Petaluma man who can't care for himself due to a brain injury went missing Monday night while on a bike ride and remained gone Tuesday morning, police said.

It's the third time in recent months that John Wirth, 49, has disappeared while on a bike ride, said Petaluma police Tuesday.

His rides in recent months have taken far from home. In June he was found in Fairfield and in May he turned up in St. Helena after being gone more than 40 hours.

Petaluma Sgt. Ralph Evans said a family member called police at 8:10 p.m. Monday to say Wirth hadn't come home from a bike ride and had been gone for some hours.

Petaluma officers alerted law enforcement from neighboring counties to be on watch for the man and his red bike.

Wirth, known as "Joe," was in a motorcycle accident 25 years ago and brain damage left him easily confused. He needs help with day-to-day activities.

Because of his disabilities, when he goes missing police consider him at risk for getting hurt. In May, a helicopter and volunteer searchers were part of the effort to find him, police said.

Wirth and his sister Mary Ann Grant moved to Petaluma about a year ago, she told the Press Democrat in May after he was lost and then found.

Months back she'd gotten him a simple flip top cellphone, saying she knew he can't use it but having it could help if he got lost.

He apparently wasn't carrying the phone this time, police said.

Wirth rides a red Pacific-brand bicycle.

He stands 6 feet tall, is about 180 pounds, has brown hair, hazel eyes and a full beard.

He was wearing a blue and red striped shirt, blue baseball cap, black pants and black shoes with green trim.

Evans asked anyone who sees the man to contact Petaluma police at (707) 778-4372.