He was reported missing the next day when he failed to show up for work at the Harwood Heights Post Office.
His wallet, keys and jacket were later found in his car near Foster Avenue beach.
"We believe he has no identification on him. He does take medication for his heart, which is another reason we're very concerned," daughter Marla Wieting said.
Richard Wieting's family was organizing a volunteer search effort near Foster Beach Sunday. The group was also expected to post flyers around the area.
The missing man is described as 6 ft. tall, 185 lbs. with brown hair and blue eyes.
Anyone with information on Wieting's whereabouts is asked to contact Det. Dan Granias at (630) 372-4427.