If the forecast is looking grim, why not spend some time at Fondazione Palazzo Bondoni Pastorio? You'll be fascinated by just how many interesting facts you can learn about the past here.
You're spoiled for sightseeing choice when spending time in Castiglione delle Stiviere. Fondazione Palazzo Bondoni Pastorio is a great place to begin here, but there are plenty of other worthy sights to experience. Desenzano Castle, Il Leone Shopping Center, and Rocca of Lonato are not far from the collection of historical artifacts and will round out your day nicely.