Hi Greg...this is Danielle, resident oyster buyer. I believe this "months with an r" rule came about when there was no refrigerated transportation. In the beginning when oysters were brought into cities by rail car the summer months were definatley not a good time to enjoy this product. Obviously this has changed and it is possible to eat oysters in the summer months. However, there are parts of the country that have better(non-spawning)oysters in the summer than others. As a broad rule Canadian oysters are fine and actually great during the summer months. The ice has melted so they can be harvested and the water during this time of year is nutrient rich. The west coast oysters, Washington in particular, tend to spawn late June/early July. Sometimes, based on weather, they last longer or spawn earlier. British Columbia product tends to last the longest on the west coast, sometimes until August. The least appetizing oysters this time of year come from the Chesapeake Bay, Rhode Island, Delaware Bay and Connecticut areas. The shelf life is awful and the meat is skinny. They are weak from spawning. Hope this answered your question.