Many of us in the meteorological community have used the term Indian summer for decades. It's been around for more than a century.
In a world where the naming of things is evolving to reflect a more modern approach, the term Indian summer may be a relic.
Genesis of Indian summer
How did we get here?
The origination of the term Indian Summer first appears over two-hundred years ago. The British website www.phrases.org.uk explains the genesis of Indian Summer this way.
Indian summer is first recorded in Letters From an American Farmer, a 1778 work by the French-American soldier turned farmer J. H. St. John de Crèvecoeur (a.k.a. Michel-Guillaume-Jean de Crèvecoeur): There are many references to the term in American literature in the following hundred years or so.
Why Indian? Well, no one knows but, as is commonplace when no one knows, many people have guessed. Here are a few of the more commonly repeated guesses:
When European settlers first came across the phenomenon in America it became known as the Indian's Summer.
The haziness of the Indian Summer weather was caused by prairie fires deliberately set by Native American tribes.
It was the period when First Nations/Native American peoples harvested their crops.
The phenomenon was more common in what were then North American Indian territories.
Defining Indian summer
What meteorological conditions constitute Indian summer? Three key elements to remember here.
It's a period of abnormally warm weather.
It occurs in mid to late autumn.
It occurs after the first frost.
Indian summer A period, in mid- or late autumn, of abnormally warm weather, generally clear skies, sunny but hazy days, and cool nights. In New England, at least one killing frost and preferably a substantial period of normally cool weather must precede this warm spell in order for it to be considered a true "Indian summer." It does not occur every year, and in some years there may be two or three Indian summers. The term is most often heard in the northeastern United States, but its usage extends throughout English- speaking countries. It dates back at least to 1778, but its origin is not certain; the most probable suggestions relate it to the way that the American Indians availed themselves of this extra opportunity to increase their winter stores. The comparable period in Europe is termed the Old Wives' summer, and, poetically, may be referred to as halcyon days. In England, dependent upon dates of occurrence, such a period may be called St. Martin's summer, St. Luke's summer, and formerly All-hallown summer.
The BBC adds this characteristically British perspective.
Shakespeare also used the expression "All Halloween Summer" in Henry IV part I for a period of warm sunshine as October gives way to November. A more generic but now (sadly) politically incorrect idiom is "Old Wives' Summer". All these expressions may still be heard in various parts of Britain, but chiefly in remote rural areas. Though they are naturally much less common than they were 60 or 70 years ago. The idea there are particular times of the autumn in Britain when these warm spells might recur is a fanciful one. Detailed statistical analyses do not suggest that any one week is more favoured than any other, and in a few years autumn brings relentlessly disturbed weather with a progressive drop in temperature, and there is nothing remotely Indian summer-like at all. The origin of all these sayings has, perhaps, more to do with keeping people's spirits up during the headlong rush into winter.
A new name?
Over the past few years I've had feedback from listeners about the use of the term Indian summer. Of course, meteorologists who have used that term to describe the seasonal singularity intend no disrespect. But it does seem that we as a profession could come up with a more respectful name that is still descriptive of the phenomenon we call Indian summer.
Second summer? Last chance summer?
The Weather Lab suggestion box is open.