A dynamic packing system places one or more perishable items into a shipping container and dispenses thermal control components therein. There is a data processor and a database including one or more order data set each defined at least by an itemized list of purchased perishable items and an order shipment destination address. A network interface is connected to the data processor, and weather data is retrieved over the network interface from a remote source. A dispenser controlled by the data processor positions a specific amount of a thermal control component in the shipping container. The specific amount is based upon an evaluation of one or more temperature values corresponding to the weather data along a transport route of the shipping container.