Weylandt died when he fell on a fast, twisting descent of the Passo del Bocco close to the finish. He was 26.
Riders bared their heads and some crossed themselves during a minute's silence, also commemorating the death of the mayor of Horsens, Jan Trojberg, who died suddenly on Sunday.
The race PA system then re-broadcast the commentary from stage three of the 2010 Giro which Weylandt won.
“[Weylandt's crash] was really sad, a young guy taken too early, something that never should happen," Britain's Mark Cavendish, the stage two winner on Sunday, told Reuters.
“"There are guys here racing today who were very close to him."