Trends of Extreme Wind Chill Temperature across Canada and the United States

Numerous studies have focused on seasonal extreme air temperatures and their trends, but there has been very limited research into extreme wind chill temperatures (WCTs). This project examined hourly surface data from 156 stations across the United States and Canada and statistically determined mean and the coldest 1% of WCTs, defined as the extreme WCTs, for the decades of the 1980s, 1990s, 2000s and the 30 year normal. Linear regression analysis was used to determine the trends for each decade. The results for decadal mean WCTs, decadal extreme WCTs and decadal trends in extreme WCTs were then spatially analyzed using ArcGIS. The results showed cooling in both decadal mean WCTs and decadal extreme WCTs in northern and western Canada and Alaska from the 1980s to the 1990s. Additionally, there was warming from the 1990s to the 2000s for decadal mean WCTs and decadal extreme WCTs for the western and southern United States and Alaska. Finally, the decadal trends in extreme WCTs show cooling trends for a majority of the United States and Canada in the 1980s, warming trends across most of the United States and Canada in the 1990s, and slight cooling trends across most of the United States and eastern Canada in the 2000s.