Intraseasonal Variations of Winter Wind Chill Temperatures across Canada and the United States

Abstract

AbstractWind chill temperature (WCT) is a measure of the human sensation of cold and also is a parameter used to represent the severity of winter weather. This study provides a unique investigation to quantify the spatial patterns of monthly mean, extreme, and severe WCTs across Canada and the United States. WCT was examined across 45 winters (December–February) spanning 1969/70–2013/14 using 156 surface locations reporting hourly meteorological conditions. Intraseasonal analyses of WCT showed that January had 1) the coldest mean WCTs, 2) the most extreme WCTs as statistically represented by the coldest 1% of the monthly WCT frequency distribution at each surface location, and 3) the greatest frequency of severe WCT hours that were ≤ −32°C. The most extreme WCTs were most often located in the Hudson Bay region of Canada, and north-central and northeastern North America experienced the largest monthly changes in WCT during the winter season. Results suggest that intraseasonal changes of air temperature are the primary influence on variations of WCT and that changes of wind speed are a secondary factor.