A magneto-caloric thermal diode assembly includes a magneto-caloric cylinder with a plurality of magneto-caloric stages. A length of one of the plurality of magneto-caloric stages is different than a length of another of the plurality of magneto-caloric stages. Each of a plurality of thermal stages includes a plurality of magnets and a non-magnetic ring. The plurality of magnets is distributed along a circumferential direction within the non-magnetic ring in each of the plurality of thermal stages. The length of each of the plurality of thermal stages corresponds to a respective one of the plurality of magneto-caloric stages.