According to @Itstrainingtime, it cannot be Indian Summer until we have a freeze in our pockets, so it had not started until now :-). With that said 1) Damn you Cautantowwit and 2) Make sure 'Myra's stockades are guarded next week! But according to these rules it can only occur over a 9 day period!
In the fall, it seems that almost any warm day is referred to as an “Indian summer.” What is an Indian summer and where did the term come from? Find out…
What Is an Indian Summer?
You may hear the term used to refer to any period of unseasonably warm weather in autumn, but traditionally, “Indian summer” referred to something more specific. Here are the criteria for a true Indian summer:
As well as being warm, the atmosphere during Indian summer is hazy or smoky, there is no wind, the barometer is standing high, and the nights are clear and chilly.
A moving, cool, shallow polar air mass is converting into a deep, warm, stagnant anticyclone (high pressure) system, which has the effect of causing the haze and large swing in temperature between day and night.
The time of occurrence is important: The warm days must follow a spell of cold weather or a good hard frost, but also be before first snowfall.
The conditions described above also must occur between St. Martin’s Day (November 11) and November 20. For over 200 years, The Old Farmer’s Almanac has adhered to the saying, “If All Saints’ (November 1) brings out winter, St. Martin’s brings out Indian summer.”
Why Is it Called an “Indian Summer”?
In parts of Europe, a similar phenomenon is known as an “Old Wives’ Summer” or “St. Martin’s Summer,” but how did the term “Indian summer” come to be? There are many theories, but none is confirmed.
Some say the term comes from the Algonquian people located in what is now the northeastern United States, who believed that the condition was caused by a warm wind sent from the court of their southwestern god, Cautantowwit (“great spirit”).
Yet another claim involves European settlers in New England. Each year, they would welcome the arrival of cold, wintry weather in late October when they could leave their stockades unarmed. But then came a time when it would suddenly turn warm again, and the Native Americans would decide to have one more go at the settlers. “Indian summer,” the settlers called it.