The descent of the icon of the Madonna di San Luca is repeated every Sunday before Ascension Day and is an established tradition of Bologna. It all begins in in 1433: from April the city was also hit by a series of incessant rains that went to hit the crops, foreshadowing a great famine. Only the procession with the image of the Madonna, brought to the city from the Hill of the Guard put an end to the rains. For this reason its descent is always accompanied by rain.