Terrace saw close to a 60 degree Celsius difference between its highest and lowest temperatures in 2021, making it the biggest gulf between temperatures in a year since 1985 and fourth largest since Environment Canada started tracking data in 1955.
Terrace’s hottest day last year was on June 27 when the temperature hit 35.6 C. That is the single hottest day on record since 2009, when it reached a recorded all-time high of 37.3 C.
On Boxing Day (Dec. 26), the thermometer plummeted to minus 21.9 C, which was the coldest day since 2012.
That means people in Terrace experienced a temperature swing of 57.5 degrees in 2021, topping 2020’s temperature difference of 55.8 degrees.
Only three years since 1955 saw a larger difference in temperatures. In 1985, the difference was 58.3 degrees, 1971 was 58.4 degrees and 1969 saw a 58.9 degree difference in Terrace’s highest and lowest temperatures that year.
Terrace’s relatively extreme temperatures in 2021 can be attributed to two events. In the summer, a stronger than usual heat dome hovered over much of B.C., Alberta, parts of Yukon and the Northwest Territories, shattering temperature records in several locations. That phenomenon was a ridge of high pressure which trapped warm air beneath it. Acting like a dome, that ridge allowed the sun to crank up the heat below.
The coldest temperature in 2021 was helped by an Arctic outflow. Another ridge of high pressure over B.C. brought strong and cold outflow winds through the coastal region. While the temperature was just below minus 20, wind chill values made it feel like it was below minus 30 C.