Not only was there no snow in southern Ontario, but the temperatures on Christmas Eve were decidedly balmy, setting new records. In Kitchener-Waterloo, the temperature on Christmas Eve was 14.7 C, shattering the previous record high of 12.8 C, set in 1964 at the Galt and former Kitchener downtown weather stations.</p>
The University of Waterloo Weather Station summary has described December 2015 as “the warmest December on record.” The summary also noted that “the warm temperatures resulted in only 8.5 cm of snow during the month, which is much below the average of 37 cm” and concluded that this December “at six degrees above average… beat the previous warmest one back in 1923 by a full two degrees, which in meteorological terms is incredible.”
David Phillips, a senior climatologist with Environment Canada, has attributed this year’s balmy November and December to the super El Niño that has formed in the Pacific Ocean.
El Niño — the Spanish word for “the Boy Child,” a reference to the birth of Christ — is essentially a weak, warm current of water appearing in the Pacific Ocean along the coast of Ecuador and Peru. The Environment Canada website describes El Niño as “a temporary change of climate that happens every few years, when winds shift in the Pacific Ocean along the equator, warming the water more than usual.”
Environment Canada has reported seven super El Niños since 1950, the last one in the winter of 1997-98, which brought the January Ice Storm to Ontario and Quebec.
According to Dr. Barry Turner, a University of Waterloo graduate based in Montreal and an accredited consulting meteorologist by the Canadian Meteorological and Oceanographic Society, El Niño can affect the jet stream over North America in such a way that it shifts to be more from the west and less from the northwest. This results in less frequent colder air from the north over southern Ontario, usually translating into a milder winter. Turner defines the jet stream as “upper air winds that ‘steer’ surface weather systems (highs and lows).” He notes that December 2015 “does appear to have been the warmest December in the Waterloo area for over 40 years, probably longer than that.”
Most meteorologists, including Turner and Phillips, are expecting the warm weather to continue into January and a shorter, milder winter this season. Turner confirms that the current El Niño event is likely to result in a higher-than-average temperature for January 2016.
However, as the National Post reports, a milder winter is not an absolute certainty. According to the National Post, Phillips has looked at Ottawa data from the seven super El Niños and found that six winters were warmer than average, but one was colder. The National Post also reports that Phillips found four of the seven El Niño years had less snow than average, but three had more. So, while a milder winter in southern Ontario is certainly possible, there are no guarantees as to what an El Niño year will actually bring.