Spring. It's like someone turned the lights on. The grass is green and long. The smell of freshly mowed lawns lingers through the air. The flowers are blooming--the tulips are singing! Spring is a great time to visit the many "marchés" (open air markets) of Paris.
Marché aux Fleurs (Flower Market)--at Place Madeleine, or Ile de la cite.
Marché aux Puces (Flea Market) There are a couple of scarily large flea markets in Paris, but the one I prefer is at Porte de Vanves, and there are some really interesting antiques there. It is a quintessential Parisian experience--jolly and convivial sellers mingling with folks. There's even the occasional accordion player.