When the temperature dipped Sunday night, and it looked like rain for hot designer Alexander Wang’s latest fashion show on a rooftop near the South Street Seaport — Anna Wintour was seen getting up before any models hit the runaway.

Some insiders even thought she’d left.

But an organizer explained, “We actually moved Anna near a side panel because it was a bit chilly . . . she stayed for the entire show.”

The night — a departure from Wang’s “guerrilla” show (performed in a nontraditional setting) on a dead-end street in Bushwick last fall — got high marks from Vogue as “hyperstyled yet still quite street.”

Runway director Nicole Phelps added: “Blustery conditions aside . . . it was the most fun I’ve had at an Alexander Wang show in a while.”

Also in the front row were Rosie Huntington-Whiteley with rappers Pusha-T and A$AP Ferg.

Models including Bella Hadid and Kaia Gerber walked in the show.