The two best windows are late March to early April for the cherry blossom — the castle moat lit at night is one of the most photographed scenes in central Japan — and early autumn (late September to October) for clear weather and good views of the Northern Alps. Summer (July–August) is humid and warm in town but is the only time to walk the Kamikōchi high valley, which is closed by snow the rest of the year.
The Matsumoto Bonbon is a giant street-dance festival in early August, with thousands of dancers in yukata moving through the centre. The Saitō Kinen Festival (now the Seiji Ozawa Matsumoto Festival), one of Japan's leading classical music events, runs through August and early September.
Winter is cold but stable, with snow but rarely deep in the town centre. The castle in light snow is a sight worth bundling up for.