It was a bitter year for farmers in both America and Europe as their crops froze, were replanted and froze again. On the Fourth of July, men of Plymouth, Connecticut wore heavy overcoats as they played quoits in the bright sunshine. Snow fell in Montreal on June 6 and 8 and Quebec City had a 12-inch accumulation on June 10. The accepted explanation is that several major volcanic eruptions in those years loaded the atmosphere with dust which girdled the globe. The dust does a better job of keeping the sun's radiation out than keeping the Earth's in and so causes the average temperature to lower by a degree or so.
Local effects can be much more severe, as unfortunate farmers have found out.