Indian Summer: What, Why, and When

What is an Indian Summer?

November 9, 2018
Fall Road

In the fall, it seems that almost any warm day is referred to by most people as “Indian summer.” And while their error is certainly not of the world-shaking variety, they are, for the most part, mistaken.

What Is an Indian Summer?

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.
  • 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.”

Indian Summer

Why is it Called an Indian Summer?

Why is Indian summer called Indian summer? There are many theories. Some say it comes from the early Algonquian Native Americans, who believed that the condition was caused by a warm wind sent from the court of their southwestern god, Cautantowwit.

The most probable origin of the term, in our view, goes back to the very early settlers in New England. Each year they would welcome the arrival of a 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. Watch a video from Editor-in-Chief Judson Hale about the origin of Indian Summer.

Are you experiencing Indian summer conditions in your area? Let us know in the comments below!

Also try our delicious Indian Summer Applesauce or Indian Pudding on your next Indian summer day.


The 1985 Old Farmer's Almanac


Reader Comments

Leave a Comment

Beautiful autumn here on Long

Beautiful autumn here on Long Island. But no red or orange in the trees. Perhaps due to the incredible heat this summer? The leaves are all yellow, with few exceptions. Usually when the green fades with decreasing chlorophyll production, we get scarlets, clarets, tangerines... not this year. Only the Japanese maples are red. Even the Bradford and Chanticleer pears which generally can be counted upon for vivid colour are almost a muddy reddish=brown, like the dregs of old wine. VERY old wine. But the temperatures are pleasant, and if we got a really hot day, I could still consider a (brief!) swim in LI Sound.

I have always heard Indian

I have always heard Indian Summer are the two weeks of warm weather after the first hard frost.

We have had beautiful fall

We have had beautiful fall weather this year in the Ozarks. Our temperatures have been above normal. Our forecast for this weekend is showing the first below 40 degree temperature since last winter. Our leaves did not seem to have quite the colors they usually have in my particular area which is in North Central Arkansas.

In North Central Ohio the

In North Central Ohio the leaves are having such vibrant colors. There has already been frost, cold weather, especially at night, with very mild temperatures (60 degrees) occurring now. This is our INDIAN SUMMER now. Thanks for sharing your information.

We've had a beautiful autumn

We've had a beautiful autumn here in Wisconsin, but with no hard frost I don't consider it an Indian Summer. I agree with the almanac that after a hard frost (and all the leaves are on the ground) a spell of warm weather is considered "Indian Summer".

An Indian Summer begins today

An Indian Summer begins today (Nov 4) in Saskatchewan. Temps are forecasted to be 10 to 15•C above normal, with temps near freezing at night. Air pressure is high, around 1023 mb. Also, no precip in sight. Going to enjoy it while it lasts!

It was 80 degrees in

It was 80 degrees in Summitville Indiana today and supposed to reach upper 70's tomorrow. I believe we are experiencing an Indian Summer here as well.

Although it's not November

Although it's not November yet, 80 degrees three days before Halloween is rather warm for West Des Moines, IA this time of year.

In Lexington, Kentucky we are

In Lexington, Kentucky we are experiencing an Indian Summer right now and for the next few days. It is 80 degrees today which breaks a record for the highest historical temperature.

Indian Summer

We are experiencing an very warm Indian Summer in Santa Fe, NM

Indian Summer

We experienced what is described as Indian Summer here in Washington DC last week. I am now reading a book where the story takes place in Paris and there is s reference to Indian Summer. I thought Indian Summer was only an American experience. So I decided to investigate the origin and meaning of the phrase

Indian summer in New England!

It's an Indian summer here in Boston that's about to come to a close. It's shocking, though it comes every year and being a true New Englander I know that odd temperatures at odd times of the year are bound to happen. Last winter, there was a day in February where I was walking around in a t-shirt!

Indian Summer

I'm in the Northwest corner of CT and we have been having days in the 80's (October 17, 18 so far) I wouldn't mind if it lasted until December. :)

indian summer

My mother always said you can't have Indian Summer until you have Squaw Winter (frozen precipitation) Here in SE Mich we had graupel ( small weird shaped chunks of ice also called soft hail) on Nov 7th. We enjoyed several days in the 70s earlier a few days before. So according to Alice, we can now have an Indian summer.

Indian summer

The temp in Charlottesville today 11/05/15 was 78 degrees @ 4p.m. Frost occurred in October did we experience Indian Summer .


No it is in November

SW Michigan Indian Summer

We are certainly having an Indian Summer day on our homestead today, The Small House under a Big Sky in SW Michigan. It is 70, clear and our sky is a brilliant and bright blue. Our Lab Sassy is out on a blanket checking on a bone, our chickens are free ranging in the sunshine pecking at worms under the oak leaves. I am raking and cutting back perennials on our 5-acre property. I'll be eating lunch out under the trees soon. A glorious autumn day!!

Hudson Valley NY

We're having and going to have a great week here in the northeast with warm days of 70 degrees and then cool nights. Interesting cloud formations with blue and red skies, it will last all week into the weekend. Not sure if this is technically Indian Summer though, as it does not coincide with the dates given in the almanac.

Indian Summer

Had an Indian Summer last night in the mid North East. We had a cold spell for a few days and yesterday around 4:00 pm it gently blew in. I just stood on my porch for hours soaking it in until it was taken over with the chill of the evening. Praying it happens again tonight....we'll see