Dear Tom,
I have heard many definitions of “Indian Summer”, but is there a single good definition?
Roger McCall, Chicago

Dear Roger,
No single definition exists because “Indian Summer” means different things to different people. Indian Summer is generally accepted as a period of a week to ten days in length, often when tree leaves are changing color or falling, in late October or early November. However, there are no fixed dates of occurrence.

Indian Summer is a period of sunny and pleasant, dry and unseasonably warm weather with hazy skies and light winds. The relative humidity is usually quite low. In the central and eastern United States it occurs from late October through the end of November, but it does not occur every year and in some years there may be more than one occurrence.

Depending on the region of the country, it may or may not be required to follow the first frost of the season. New Englanders, for instance, require at least one killing frost before a true Indian Summer can begin. Frost or not, Indian Summer always follows a substantial period of cool weather. The cold of winter usually follows in fairly short order.

The origin of the term, Indian Summer, is uncertain, but it originated in New England and its usuage has been traced back to at least 1778. One account is that American settlers named the period after being told of such spells of pleasant weather by Native Americans who considered the good weather a gift from Cautantowwit, the God of the Southwest.

The earliest known use of the phrase, Indian Summer, is in an essay written in the United States in 1778 by J. Hector St. John de Crevenoeur. He wrote, “Sometimes the rain is followed by an interval of calm and warm (weather) which is called the Indian summer.”