I ride my bicycle in all seasons, even when it is -24 C or +30 C. But I like summer most. Our bicycle paths are maintained in all seasons, but in summer there are many city parks where one can sit on benches. Also you do not need to be worried about ice and snow.
I had the honeymoon trip to Maine three decades ago. We did a lot of hiking in Acadia National Park. Watching the sunset from Cadillac Mountain was beautiful. Maine is a beautiful State. We went to Bar Harbor and did some sailing there. Those were good times. @nate_malloy