Temperature highs that vary from day to day do not necessarily constitute proof of global climate change, but the intensity of the current warm spell, as well as its duration, are breaking records.
Winter across the prairies of Canada started late in 2016, yet it struck with vehemence come December.Manitoba temperatures plummeted precipitously with overnight lows dipping into the minus-30s by the middle of the month.This built an expectation of continued cold and snow as per the usual winter, which would be a return to normal.
The latter half of December delivered on this expectation, and the cold carried through New Year's; however, by the middle of January, Saskatchewan and Manitoba broke multiple heat records for the month.This seems unusual, at least on principle, until compared to trends from recent years.
In the last 10 years, approximately 60 percent of the winter months (November to March) in southern and central Manitoba have exhibited above-average temperatures.Another 10 percent of those months hovered around average temperatures, and only 30 percent ranged below average.
The majority of the months that registered below-average temperatures were in 2013 and 2014 specifically, which was when much of the region was afflicted by an extreme Arctic vortex.The coldest month was also registered during this time.
The warmest months are the more recent months such as February 2016.This suggests that the trend of unusual weather is becoming the usual weather - no matter how often we call it unusual.