When should I visit Bologna, Italy, for the best experience?

Bologna's weather is the Po Valley's: winters cold and fog-bound (the famous nebbia), summers genuinely hot and humid with highs into the mid-90s°F (35°C), and two sweet shoulders in between. May is the finer of them. Days run 68–77°F (20–25°C), the city's roughly 38 miles (62 km) of porticoes — the arcades that UNESCO inscribed in 2021 — carry their original purpose of sheltering walkers from sun and rain alike, and the university, founded in 1088 and the oldest in continuous operation in the Western world, is in full term: Bologna in May is La Dotta, the Learned, awake and outdoors.

May also holds the city's defining devotion. During the week of the Ascension, the Byzantine icon of the Madonna di San Luca — kept all year in the sanctuary on the Colle della Guardia above the city — is carried down the great portico (666 arches, 2.4 miles / 3.8 km, the longest in the world) in a procession that has run since 1433, spends days in the cathedral receiving the city, and climbs back again. No other week shows you what Bologna actually is: a working, eating, believing city rather than a museum. It is also prime eating season — spring vegetables, the first outdoor tables in the Quadrilatero market lanes, asparagus and early cherries from the Vignola hills — before August empties the city and closes half its kitchens.

The close rival is late September into October: truffle and mushroom season in the hills, cooler air, the university back. But October brings the fog's first returns and shorter days, while May gives you 15 hours of light, the procession, and the city's gardens in flower.

A May evening under the porticoes of Via Zamboni: students spilling from the university palazzi with spritzes in hand, the arcades amber in the long light, and somewhere above the rooftops the Asinelli tower standing over a city that has not yet slowed for summer.

Bologna's May secret is how completely it is a term-time city: the great food shops of the Quadrilatero, the student osterie, the markets — all run at full power in May and quietly shutter in August, when the Bolognesi leave for the Adriatic coast 50 miles away and some of the most famous trattorias close for weeks. The calendar tourists consult least — the university's — is the one that decides the city's mood.

• Aim for Ascension week — Check the year's dates for the Madonna di San Luca processions (the Descent falls in mid-to-late May) and build the trip around them
• Walk the San Luca portico — Climb the 666 arches on a weekday morning, when the runners and dog-walkers have it, not on procession days
• Eat spring — Order the season's first tortelloni with ricotta and herbs, and Vignola cherries from the market stalls

May weekends bring the year's peak hotel prices for a city that also hosts trade fairs at BolognaFiere — big fairs (watch for Cosmoprof in spring) can triple room rates across the center, so check the fair calendar before fixing dates. June's Cinema Ritrovato (late June) is glorious for film lovers but equally full. And the summer heat, when it comes in July, is the humid Po Valley kind that the porticoes mitigate but cannot cure.

Fix May dates with Ascension week at the center, book a centro storico hotel early, and keep one morning sacred for the San Luca climb.