Walking through the arches makes you feel protected and cosy, you don´t feel like being outside, it´s more an extension of the indoor. Bars and restaurants have tables under the portico all year long, (many bars are so small, they actually need that extra space) just the drinks change with the season:
In summer you have “caffe shakerato” (iced and shaken coffee), in winter hot chocolate, which is very thick, you literally need a spoon to eat it. In the 13th century the population raised rapidly because of the famous University, but there was no room inside the walled city, so they started to build extensions over the sidewalks – it added up to 40 km covered sidewalks in the historic center. There are still some spots where you can see the wooden construction, for example at via Santo Stefano, others are beautiful painted like in via Farini – just don’t forget to look up every now and then when you stroll the historic center of Bologna!