L'Aquila's altitude (700 metres) keeps it cool even in summer — temperatures in July and August are genuinely comfortable, rarely exceeding 30°C, making it a relief after Rome or the coast. Winter is cold and often snowy; the surrounding mountains make the city beautiful under snow but also occasionally cut off. Spring and early autumn are ideal: the mountain air is clear, the wildflowers are out in the surrounding hills, and the city is at its most liveable.
The Perdonanza Celestiniana, held on August 28-29 each year, is L'Aquila's major annual festival — a UNESCO-recognised event centred on the opening of the Holy Door at Santa Maria di Collemaggio. It brings pilgrims and visitors to the city and is worth timing a visit around.