These data include two spreadsheets. The first is average daily temperatures received via satellite transmitting collars deployed on polar bears in the southern Beaufort Sea 1986-2013. The second is denning classifications for adult female polar bears in the southern Beaufort Sea using the temperature data. Denning was classified using a control chart-based algorithm applied to the temperature data received from the collars. This method was validated by comparisons with a previous study, direct observations during flights to track collared bears, and observations of females with newborn cubs the following spring. Further information is available in the methods.