Rat snake populations from their northern range, such as Ontario, are experiencing a shift in hibernation emergence. The populations in these regions typically emerge from hibernation in late April. However, the increasing variability in temperature may cause rat snakes to emerge on a warm sunny day in the months of February or March. Climate change has caused winters that can have weather turn back very quickly from sunny periods with high temperatures to snow and below freezing temperatures. The early emergence of these rat snakes will begin to expose them to these fatal conditions if a snake cannot return to its hibernaculum in time. Therefore, the fluctuations in temperature affect the thermoregulation that rat snakes need for bodily functions like digestion and movement. The unpredictability of the weather is causing more rat snakes in their northern range to get caught in these cold snaps and freeze to death.