The Scheffer Index for wood decay potential above ground provides guidance in planning design and treatment strategies to ensure the durability of wood products. Work to improve its predictive capability was sidetracked by finding values calculated from recent climate data were higher than those from the literature; likely a result of climate change. This led to development of an updated North American decay hazard map for comparison to a map created using published data. We found considerable expansion of the moderate decay hazard zone, particularly in the interior wet belt of British Columbia, across the northern edge of the Prairies and around the Gulf of St. Lawrence. Experience with decay of pine shakes in Edmonton suggests this may have practical implications for the durability of wood in service. It may also affect decay of woody debris and standing dead trees such as those killed by the mountain pine beetle.