On average, the curing time for most commercially available silicone caulks is 24 hours. The curing time for silicone caulk varies and is dependent on several factors, such as the brand, type and quality of the caulk; humidity, location, heat and exposure to light. Although silicone caulks will feel dry to the touch in about 30 minutes to an hour, this does not necessarily mean that the sealant has cured.
Sometimes referred to as a silicone sealant, caulks do not dry. Caulks cure, which means that the curing agents that formulated within it become active and are working. It is also advised to check the "Use Before" date on the packet as silicone caulk can lose its ability to cure.
During its curing process, silicone caulks require moisture from the air. This means that the curing time for silicone caulks will be faster in areas with high humidity and slower in places with dry climates.
Silicone caulk is made from silica sand that is processed into a basic a silicone oil polymer. Additives, such as clay and a mineral called mica, is added into the silicone oil polymer to give it body. Silicone caulk is recommended for use with non-porous materials like glass and metals.