April to June and September to October are the best months. Spring brings blossoming gardens and clear air; autumn turns the hills gold and the Prosecco harvest is underway in the surrounding vineyards. Temperatures are mild and the light is extraordinary.
July and August are warm to hot and the town gets busy with Italian summer visitors, though Asolo never crowds to the point of unpleasantness. Winter is quiet — some restaurants and shops close — but the views to the snow-covered Dolomites on clear days are spectacular.
The Mercato dell'Antiquariato, one of the best antiques markets in the Veneto, takes place on the second Saturday and Sunday of each month in Piazza Garibaldi. If you're a serious buyer, plan around it.