Spring snow always comes as a bit of a shock, particularly when it follows an early warm-up, but it happens with some regularity in our region. Historically, late-season snowfall is related to latitude and local geography. For Fargo, the historical record indicates an 88% chance of measurable snow during April and an 18% chance of getting measurable snow during May. Further south, Rochester can expect measurable snow in just 58% of Aprils and just 8% of Mays. On chilly Lake Superior, Duluth has gotten measurable snow in 93% of Aprils and 34% of Mays.
Further west, where the climate is more arid but the elevation is higher, Bismarck gets measurable snow in 85% of Aprils and 26% of May months. In all cases, the odds of getting heavy snows of 6 inches or more are much less common than the odds of getting lighter snows, particularly in May, when heavy snows are truly rare throughout the region.