Composting with worms operates year-around. You can place your wormery either indoors or outdoors. It is important to always ensure that the earthworms have an optimal temperature of approximately 20 C/ 68 F as well as a correct level of moisture in the substrate.
During winter you shouldn't leave your wormery without insulation, so it doesn't freeze through. In the summer it shouldn't be exposed to direct sunlight, to prevent water evaporation and overheating. The temperature in your wormery should not drop below 5 C or exceed 25 C.