Suction cups are used to mount items such as a GPS unit in a car or a shower rack in the bathroom. The suction cup creates a strong vacuum seal that holds it in place. If the surface to which you're attaching the suction cup or the cup itself gets too cold, then the seal isn't going to be as strong as it needs to be. There are ways to remedy this problem so you can continue to use your suction cup through all kinds of weather.
Heat up the area to which you're attaching the suction cup. Depending on where the suction cup is going, this process can include parking your car in a garage or turning on the heater, spraying your shower wall with hot water or simply rubbing the area with your hand to create friction heat.
Clean the area thoroughly with spray cleaner and a paper towel.
Clean the suction cup with warm, soapy water. This will remove any dirt and debris from the suction cup; it also will warm it up and make it more pliable. Rinse the suction cup with warm water.
Press the suction cup firmly against the desired surface while still wet.