Calgary’s biggest-ever snowstorm hit the city in May
May has a history of producing Calgary’s biggest-ever snowstorms
A gloomy Tuesday in May provided few clues that Calgary, Alta., would shatter an all-time wintry weather record just a few hours later.
Calgary’s largest-ever snowstorm unfolded on May 6, 1981, a Wednesday that saw a whopping 48.4 cm of snow plaster the metro area.
This record-breaking storm cemented the city’s reputation as a springtime snowfall juggernaut, churning out impressive amounts of winter weather long after winter seemingly ended.
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Calgary is no stranger to snow in the spring. After all, the season averages more snow in March, April, and May, than it does through the winter months.
But what played out in late-spring 1981 was a truly historic event.
Unseasonably chilly temperatures bathed Western Canada to begin the first full week of May as a sharp upper-level trough dug over the region.
The temperature in Calgary only reached 11.6°C on Tuesday, May 5, which was quite a bit below seasonal for the start of the month. Overcast and showery conditions accompanied the chillier-than-usual conditions over the Alberta foothills that day—hardly a harbinger of what would come next.
Readings fell in a hurry through Tuesday evening and into the overnight hours, dropping near the freezing mark by the Wednesday morning commute.
And then the rain changed over to snow.
“Soaked Calgarians slipped and slithered to work this morning, many having left their homes in darkness as the sudden return of winter brought widespread power failures around the city,” the Calgary Herald reported that morning as the heavy, wet snow plastered the region.
Steady northeasterly winds blew across the Calgary area all day on May 6, enhancing snowfall rates throughout the region.
Adding fuel to the wintry engine was a low-pressure system in the U.S., along with a centre of high pressure over the central Prairies, that combined forces to blow enhanced moisture north of the border. This is a scenario we see repeatedly on the western Prairies during the spring months.
By the end of the day, weather observers at Calgary International Airport had recorded 48.4 cm of snow—making for the city’s largest single-day snowfall ever measured, a record that still stands as of 2025.
Given marginal temperatures hovering just above freezing, a higher sun angle, as well as a transition from snow back to rain, the snow on the ground didn’t linger very long. The airport only reported 8 cm of snow on the ground by Thursday, May 7.
Calgary’s historic snowstorm of 1981 found itself in good company. All five of the city’s biggest one-day snowfall events occurred in the middle of spring, and four of the five unfolded during the month of May.