To know it's summer...

When morning light rises on the horizon north of the misty river...



and black-eyed susans raise their faces to the sun


and 'skeeters in the wet grass nibble at our ankles  while lacey-winged dragonflies cling to twigs and branches  and along the barb-wire fence  and skip across the pond in search of a meal... ...you know it's summer.   
As soon as they come out in leaf,
you see for yourselves
and know that the summer is already near.
Luke 21.30

What about you? How do you know it's summer where you live?