Abstract: An impervious contour closure for preventing air flow through a swamp cooler and related methods, which can be easily and quickly utilized by a lay person having little or no technical training. Installation of the novel closure requires no alteration to the cooler itself, effectively seals against an interior and exterior building wall around the cooler against air flow through the cooler, and provides an attractive appearance. In the spring, the steps of installation can be facilely reversed to implement the cooler for use during warm and hot weather.