Weather Whys

By Texas A&M University —

Q: Does an “Indian Summer” occur everywhere in the U.S.?

A: Technically, no, says Brent McRoberts of Texas A&M University.
The term “Indian Summer” is rather vague and has been around at least
300 years. “According to the American Meteorological Society's Glossary
of Weather, an Indian Summer is in mid or late autumn, of unseasonably
warm weather, generally with clear skies, sunny but hazy days and cool
nights. In New England, at least one killing frost must precede this
warm spell for it to be considered a true Indian Summer,” he points out.
“But the book says that often, two or three Indian Summers can happen
in one year. Most people believe Indian Summers occur only in New
England or the Midwest, but they can happen almost anywhere.”

Q: Where else do they occur?

A: From the mid-Atlantic states to New England are the prime Indian
Summer locations, but they also can occur in the Great Lakes region, the
Ohio Valley, all along the Great Plains and even the Pacific Northwest,
he adds. “Usually, the term refers to locations that have a true
winter, so Florida or parts of the Gulf Coast probably don't have true
Indian Summers. The term has been used since the 1700s to describe warm
days during autumn, and in the 1855 poem Hiawatha , Longfellow mentions
it, writing, “Gave a twinkle to the water, touched the rugged hills with
smoothness, brought the tender Indian Summer to the melancholy north
land.”