SEPTEMBER is basically the last month for yard sales and open air flea markets. Because it gets colder. But not because the cold kills the fleas.
The word flea market is originally Dutch: “vallie” market. These were markets where farmers offered their merchandise, in the valleys above New York, then New Amsterdam, and on the Lange Eylant, now Long Island. The merchandise was not limited to food; one could also buy pots, pans, some furniture and clothes, used or otherwise, at these vallie markets. Vallie soon became vlie, and as Dutch words became phoneticized, vlie eventually became spelled flea. The term then emigrated back to Europe, where it was henceforth mis-translated everywhere.
Flea markets, yard sales, garage sales: as Dutch as a valley between the hills and the river.