Danish model Caroline Brasch Nielsen, after A Show, NYC, September 2012.
An excellent way to deal with the unpredictable summer weather: slip a leather jacket over a pretty summer dress and team with (Chanel!) espadrilles. 
Recreate Caroline's look (kind of):
3.1 Phillip Lim Peplum moto jacket,  or 3.1 Phillip Lim tiger-print leather jacket
Free People Arbor dress, Twelfth St. by Cynthia Vincent Western lace dress, Free People Meadows of Lace dress, DKNY racer back dress or Twelfth St. by Cynthia Vincent belted high-low dress
Soludos Biarritz colourblock espadrilles, Soludos classic stripe espadrilles, Valentino mesh lace espadrilles, Enzo Angiolini espadrilles, ASOS Jessie espadrilles,  Christian Louboutin Galia striped espadrilles, or Stella McCartney zebra-print espadrilles