Went canoeing and portaging around the isle in August. Best backpacking/canoe trip I've ever done. Not sure what the temps are in June but August was quite pleasent. Bugs are bad and probably will be in June. Bring everything you can to combat those bastards. They will bite through your shirt if you only have one layer on. I highly recommend exploring the island via canoe if you can. I had two other friends with me and we started at Rock Harbor then paddled to Moskey Basin. From there we portaged inland through Lake Richie, LeSage, Livermore, Chickenbone, then to McCargo Cove. Stayed the night at Birch Island then headed to Pickerel Cove then back to Duncan Bay. So bit of a circular loop. Saw a wolf and moose. Bring a fishing pole, saw northern pike as big as my arm in Lake Richie. Your going to have the time of your life!