Sondrio to Siderno trains might be a good value for money solution: travelling in Italy by train is often rather cheap and faster than taking a bus indeed Trains leave from Sondrio and arrive at Siderno every about 2 hours on average. If travelling with Trenitalia, you need to know the Sondrio to Siderno train schedule: the first train leaves at 04:32, while the last ride is at 17:38. A Sondrio to Siderno train cost about 98.0 €. But how long is the train ride from Sondrio to Siderno? Your journey takes about 18 hours on average.