A 0.49-ha bioreactor landfill cell containing approximately 32,400 metric tons of municipal solid waste was constructed and operated at the Northern Oaks Recycling and Disposal Facility in Harrison, Michigan, USA. Design of this full-scale research cell included a network of 48 temperature and moisture sensors, leachate collection basins, and gas sampling ports, which provided for continuous temperature and moisture data and periodic measurements of both the quantity and composition of the leachate and gas produced. The data indicated that methane generation started approximately 3 months after filling in lifts that were placed during summer, but not until 8 months for those filled during the winter. Temperature data indicated that near-0 degrees C temperatures persisted within the lifts filled during winter for more than 6 months, and that gas production was minimal during this period. These results suggest that in addition to maintaining optimal moisture levels within the waste mass, temperature control must be a key design consideration in cold climates.