Our snow has melted except on the mountain ridges and we are settling into Indian summer. I read a while back that the term used to refer to late summer, maybe August, when the western skies were hazy from the fires the Indians set to clear brush and encourage plentiful grass the next spring; this source was clear that Indian summers don't occur anymore (although with our recent fire seasons, that may be debatable).
We use the term differently, to mean the period after the first hard frost or snowfall when the daytime temps are 70 degrees, the nighttime temps are in the 40s, the skies are deep blue, the air is crystal clear, the trees are vibrant with changing leaves, and the grass is silver-gold in the fields. I heard years ago that Indian summer was a derogatory term, similar to Indian giver, because it is a "false" summer, but it is my favorite time of year and I can't believe that "Indian summer" is derogatory to anyone. Indian summer encourages you to get outside, to enjoy the sunshine lying warm on your skin, to finish up those things you let slide during the heat of the ordinary summer, to prepare for the winter that you can't ignore anymore. It is time for late harvests, for hunting animals fat with winter stores, for preparing for the long nights ahead - I imagine that the Indians appreciated this season as much as I do, or more. It is our most colorful season, too; winter is whites and blues and greys, spring is browns and greens, early summer is all greens, but Indian summer brings blues and whites, browns and golden tans, greens, yellows and oranges and crimsons, all under a brillinat sun. What more can you want in a season?