Shafeek said No Pants Day in 2012 attracted around 3,500 participants, and this year there were expected to be more.
The organisers, a group called 'Improv Everywhere', encourage people to be fully clothed with coats, gloves, hats and scarves, but with no skirt or trousers.
As part of the joke, participants also pretend not to notice one another's strange attire.
Passengers went pant-less in at least 60 cities around the globe on Sunday, including London, Hong Kong and San Francisco.
