Looking at a graph of winter snowfall in Winnipeg since 1873 reveals some interesting observations. Most notable is how erratic Winnipeg snowfall is from year to year, with wild swings from well above "normal" to well below. In fact, it's tough to say what "normal" is, since snowfall varies so much every winter. One way to define "normal" is to look at a longer term average. Looking at the 30 year running average (red line), one can see that snowfall has averaged roughly 125 cm for much of Winnipeg's history since 1873. That average started to dip in the 1970s and 1980s with several below normal snow seasons during that time. As a result, our 30 year running average dipped to a low of 110 cm by the 1990s. Since then, average snowfall has been trending up again, with a trend towards that 125 cm average thanks to the last few winters. Perhaps this is nature's way of reverting back to more typical snowfall amounts for this part of the world.
|Graph of winter season snowfall in Winnipeg since 1873|
Red line shows 30 year running average (cm)
The graph also shows another interesting tidbit. The least snowy winter in Winnipeg was way back in 1877-78, during Winnipeg's warmest winter on record. Only 31 cm of snow fell that entire winter, during the "year without a winter" that was a result of an unusually strong El Nino that year that had worldwide impacts on weather, rainfall and crops. December 1877 was virtually snowfree in Winnipeg (only 0.5 cm the whole month) and no month that entire winter exceeded 8 cm of total snowfall. Incredible. (*NOTE: Some recent information suggests that Winnipeg may have experienced a significant snowfall later that spring on May 2 1878. In a Department of Transport study on the "Climate of Winnipeg" (Labelle, Brown, and Hasinoff, June 7 1966), it notes that the heaviest May snowfall on record in Winnipeg was 10.7 inches (27.2 cm) on May 2 1878. Officially in the digitized climate archives online, snowfall for Winnipeg on that date is listed as only 1.8 cm, or 0.7 inches. It's possible the data was incorrectly entered into the climate database as 0.7" instead of 10.7". Note that the nearby St Andrews climate site recorded 12" of snow (30 cm) on May 2-3rd 1878, so the potential is there that Winnipeg had much heavier snow that day than the current archive shows. I will update this info if and when I hear more.)
One last but important note. Snowfall observations are no longer taken at Winnipeg airport which was the official source for snowfall observations in the city since 1938. (St John's College took snowfall observations in Winnipeg between 1873-1938) Due to automation and a change in observing responsibilities, snowfall records at the airport stopped in 2007. Since then, snowfall readings for Winnipeg have been based on snowfall observations taken from my Charleswood observing station, an official climate station with Environment Canada. I take two snowfall readings a day from October to May, including snow depth, and send the reports to Environment Canada who archive them in their climate database. Snowfall readings at my site will not always be representative of snowfall at the airport, but at least we have some record of snowfall for the city, in the absence of official snowfall data from Winnipeg airport.