A Look into Changes in Precipitation Types Linked with Surface Air Temperature over British Columbia, Canada 1953-2005

This study attempts to understand the effects of air temperature on the frequency of snow days, rain days, and frozen rain days in British Columbia Canada. This was conducted by using historical climate observations among 12 stations from 1953 to 2001. A simple linear correlation analysis was performed to derive any changing trends and their associations with the surface air temperatures. Surface air temperature in the region has been consistently increasing over the 48 years, consistent with the global temperature trend. There also appeared to be consistent inter-annual temperature variability among these twelve stations. The annual frequency of snowfall days has been decreasing in all the twelve stations observed. It appeared that annual frequency of rainfall days did not display a clear pattern and no conclusion could be made on its connection to air temperature. The frequency of frozen rain days has increased in 10 of the 12 stations.