Not Cool: On the Loss of Cold Weather in the Canadian Arctic

Most studies of climate change in the Arctic report how much warmer the climate is getting. In this study we use 1950-2020 daily observed minimum temperatures at 34 weather stations in Canada's north to examine how rapidly the region is losing annual occurrences of cold weather (−30°C or colder). Kendall-Theil trend analysis is used to assess the strength and significance of trends. Twenty-nine of the stations were found to have significant negative trends, with an average of 4.89 fewer annual cold days per decade; on average, the stations have lost over 40% of their cold days in recent decades. An ensemble of downscaled Coupled Model Intercomparison Project, phase 5 (CMIP5) models is used to show how the numbers of cold days are projected to change in the coming decades with the representative concentration pathway (RCP4.5 and RCP8.5) scenarios. Finally, we discuss the implications of the loss of cold weather in the Canadian Arctic and beyond.