A lightweight, foldable cover adapted for attachment to a portable electric generator permits the generator to be operated while covered and shielded from weather. The cover includes rigid or semi-rigid sides hingeably joined and held in position with flexible straps. The cover allows unimpeded exhaust and airflow underneath the cover, and unimpeded access to controls and outlets. The flexible straps attach to the cover and the frame of the generator. The straps are adjustable to accommodate different generator frame sizes, and include quick release devices to allow rapid attachment to, or detachment from the generator frame for refueling or storage. When removed the cover folds nearly flat for storage.