Indian Summer

"The last rose of summer, is blooming on the lawn All her lovely companions are faded and gone..."

- Thomas Moore, "The Last Rose of Summer"

In any setting where exists a standard four season climate, there will always be an episode or chapter where it is unseasonably warm and beautiful. This will always occur at the beginning or end of summer (depending on whether summers in the area are known for being oppressively hot and humid, or blessed and carefree, respectively.)

Indian summer weather is always important to the plot, as it signifies the beginning of the last chapter in the characters' relationship -- a Romance, a Road Trip, etc. The characters are able to enjoy some carefree time together right before things start to go south.

If it is a Coming of Age Story, the last time the characters get together to have fun before going their separate ways will always be an unseasonably warm and pleasant day. Some huge relationship battle will invariably occur and separate the tight-knit group of characters by nightfall, only to have them reunite (possibly years later) in more depressing circumstances, usually in the rain.

Compare Bittersweet Ending. Inverse of It's Always Spring. Closely related to First Snow.

Contrast Dreaming of a White Christmas, Long Hot Summer.

Not to be confused with the weather in India, although the trope fully applies to works set in South Asia on unseasonably cool days.

Film

 * Grease starts with Sandra Dee and Johnny falling in love during an idyllic summer vacation at the beach.

Literature

 * From the backstory to The Lord of the Rings, Aragorn's season with Arwen in beautiful, dreamlike Lothlorien, at the end of which they get their Relationship Upgrade, and after which all the real hard work and war kicks in. It's the one time between the discovery of his lineage and destruction of Sauron that Aragorn allows himself some respite, and the summer is remembered very fondly afterwards.
 * The first Redwall book takes place during what the Abbey residents call the Summer of the Late Rose. The aptly named Methuselah says he can only remember three summers in his lifetime when the roses bloomed so late.

Live Action TV

 * This is the title of a masturbation-themed episode of Mad Men. The Indian summer causes Betty to consider buying an air conditioner from a door-to-door salesman, whom she invites into the house and later fantasizes about while she has an unplanned intimate moment with her washing machine.

Music

 * "That Summer" by Garth Brooks
 * "Strawberry Wine" by Deana Carter
 * "All Summer Long" by Kid Rock
 * "L'été indien" by Joe Dassin
 * "Indian Summer" by Brooks and Dunn
 * "A Summer Song" by Chad and Jeremy
 * "Indian Summer" by the Saw Doctors
 * "Indian Summer" by Tori Amos

Western Animation

 * In the South Park ep. "Summer Sucks" when the boys got out of school for Summer Vacation all the snow melted. This was implied to last about a month.

Real Life / Other

 * The old name for this was St. Martin's Summer, named for the feast-day of St. Martin of Tours, November 11.
 * Britain had glorious weather in October 1986. (Exactly one year later, though, there was a horrendous storm.)
 * In Britain if you even get nice weather for one day you WILL have cold and wet the next. For at least a week.