There's nothing like an all-inclusive holiday in Silz to revive you, especially when you know what kind of weather to expect. Here's some information to help you choose when to book: The hottest months are usually August and July, with an average temperature of 8°C, while the coldest months are January and February, with an average of -7°C. February and March are the driest months, while June and August are the rainiest months.