It's Summer

How do I know? Well,
1) The Rugosas have bloomed--I think it's the earliest ever for ours
2) The Lupine are blooming
3) I saw the first swallowtail of the season flit through the backyard
4) The pansies are out, the red geraniums are in
But the indisputable determining factors is:

5) There are more cars on rt. 1 with out of state plates than there are cars on Rt. 1 with Maine plates