Here's a quick glimpse at the weather recorded on Mother's Days of recent memory. All data are from the climate station at the Marquette National Weather Service office located just east of Negaunee, MI.
In short, high and low temperatures have varied greatly on Mother's Days over the past couple of decades, with highs ranging from 44 to 83, and lows ranging from 27 to 60 degrees. It appears to be quite common to see rain on Mother's Day, with only 8 of 22 years listed having dry conditions all day. And while no snow has fallen on a Mother's Day at least since 1988 in Negaunee, there have been two years where snowpack was still on the ground!
Compare to this year's forecast: