Demonstrating climate change in Prince Edward Island – A procedure using climate normals and weather data suitable for classroom use


  • David J. Garbary



A simple method to assess climate warming is described, which is suitable for post-secondary classes in environmental sciences.
This method is based on climate normals and subsequent weather data, and is demonstrated using Government of Canada archived climate/weather data from sites in Prince Edward Island including Charlottetown Airport, Alliston and New Glasgow. The method uses a simple statistical analysis based on one or two sample Student‘s t-tests as well as scatter plots and linear regression to highlight the direction and magnitude of changes. Statistically significant increases of annual average temperature of 0.7°C to 1.3°C were calculated for the period after the end of the 1961-1990 climate normals for
Alliston and Charlottetown, and a 0.9°C change was demonstrated for New Glasgow after the 1971-2000 climate normals. These values suggest a recent rate of change three times greater than a previous estimate of up to 0.9°C per century for the Gulf of St. Lawrence region, with a major temperature increase occurring in the late 1990s.
Changes were most pronounced during September and December, and two sites showed a significant increase in continuous frost-free days during the growing season, as well as a decline in the number of days with frost during spring and fall. 

Keywords: Climate change, climate normals, Prince Edward Island, weather