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Mexico is one of the two centres of diversification of oaks (Quercus spp.) in the world, with 161 species, 66% of which are endemic. The local-scale analysis of trends in climate variables, using climate indices, can be useful in estimating both the potential benefits and risks presented by climate to oak populations. Since the minimum January temperature is an important limiting factor in the distribution of Quercus emoryi Torr. in Mexico, this study analysed trends in this variable in the area of distribution of the species and identified the populations likely to be affected by them. The RClimDex 1.0 software was used to analyse trends of nine climate indices related to minimum temperature recorded in 14 weather stations in the area of the species' potential distribution in Mexico. Data from five stations showed significant trends related to an increase in minimum January temperature, whereas data from seven stations showed trends of a decrease in this variable. Populations of the species, mainly in the ecoregion containing piedmonts and plains with grassland, scrubland and forests in the Cuauhtemoc region in Chihuahua state, and Cuencame and Canatlan regions in Durango state, could be affected by these trends. The information on at-risk populations may be used for in situ and ex situ species conservation programs.